Research ArticleSurvival Analysis of Clinical Cases of Caseous Lymphadenitis ofGoats in North Shoa Ethiopia

Erdachew Yitagesu 1 Enyiew Alemnew1 Abebe Olani2 Tadiwos Asfaw1

and Chekol Demis1

1Debre Birhan Agricultural Research Center PO Box 112 Debre Birhan Ethiopia2Department of Parasitology National Animal Health Diagnostic and Investigation Center (NAHDIC) PO Box 04Sebeta Ethiopia

Correspondence should be addressed to Erdachew Yitagesu erdutellagmailcom

Received 11 June 2020 Revised 24 July 2020 Accepted 28 July 2020 Published 17 August 2020

Academic Editor Francesca Mancianti

Copyright copy 2020 Erdachew Yitagesu et al is is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited

Caseous lymphadenitis (CLA) is a bacterial disease of small ruminants causing abscesses in lymph nodes of the body and internalorgans A longitudinal study from 2011 to 2019 was undertaken at Ataye site of Debre Birhan Research Center to estimate theprevalence and incidence identify associated risk factors and characterize the causative bacteria 1025 goats were followed up forthe CLA study Survival analysis was done using SAS 94 software program Biochemical tests and Biolog microbial identificationsystemwere used to characterize the bacteria In the recurrent survival data analysis there were 1138 clinical observations and 214CLA cases (188 prevalence) based on clinical diagnosis e incidence rate was 014 cases per animal year From a total of 214cases 130 have occurred once and 84 cases are recurrent cases following first cases e cumulative failure rates were 68 fornewborn and 64 for yearling age groups e parotid lymph node was the most frequently affected site Proportional hazardanalysis results showed that sex age and breed were associated (plt 005) with CLA incidence Females newborn age group Boerand BoertimesCentral Highland Goat (CHG) were at higher risks compared to males yearling age group and CHG goats re-spectivelye present study indicated that a high incidence rate of CLA in the goat farm is difficult to control and prevent becauseof its poor response to clinical treatment us control and prevention should focus on the spread of the disease such as isolationof clinically sick animals culling and vaccination of flocks

1 Introduction

Abscess disease commonly known as Morelrsquos disease andcaseous lymphadenitis (CLA) is a bacterial disease of sheepand goat causing abscesses in lymph nodes of the body andinternal organs especially the lung It is a contagious diseasedistributed worldwide and lacks effective control measuresOnce introduced into a sheep or goat flock it is very difficultto control because of its poor response to treatment itsability to persist in the environment and the limitations indetecting subclinically infected animals [1 2] CLA is adisease caused by Corynebacterium pseudotuberculosisbacteria It is commonly found in animals such as sheepgoat and cattle from where the infection is transmitted to

humans ese bacteria are Gram-positive nonmotilepleomorphic rods (about 05 μm in width) that often presenta characteristic Chinese letter or palisade arrangement in thesmear C pseudotuberculosis is a mycolic acid-containingfacultative intracellular parasite that multiplies inside themacrophage Its natural habitat is skin mucus membranesand gastrointestinal tract of normal sheep and soil of sheeppens [3 4] Accurate CLA diagnosis is based primarily onclinical observations (external abscesses) [5] and the iden-tification of C pseudotuberculosis by phenotypic and bio-chemical tests this is important to differentiate thisbacterium from other abscess inducing pathogenic agentssuch as Arcanobacterium pyogenes or Pasteurella multocida[2 6 7]

HindawiVeterinary Medicine InternationalVolume 2020 Article ID 8822997 8 pageshttpsdoiorg10115520208822997

It causes considerable economic losses to sheep and goatproducers as it reduces milk yield and meat and woolproduction Also it decreases reproductive efficiencies It isthe main cause of condemnation of sheep carcasses inslaughterhouses in Australia one of the worldrsquos largestproducers of meat and wool [8 9] Unfortunately it is theinternal abscesses that are fatal whereas external abscessesare generally responsible for disease transmission [1] InEthiopia recent findings indicate that 15 prevalence ofcaseous lymphadenitis was reported from goats slaughteredin Luna Export Abattoir originated from district area ofBorena Range Land [10] and 10 prevalence of local abscesswas also reported in Boer goats of Adami Tulu AgriculturalResearch Center Nucleus site being the major disease next toGIT parasites keratoconjunctivitis ticks and respiratoryproblems [11] 47 prevalence of caseous lymphadenitiswas also reported from the Boer goat breeding station ofSouthern Ethiopia [12] In Ethiopia the disease was not yetcharacterized at farm level erefore the objective of thisstudy is to estimate the prevalence incidence and riskfactors of caseous lymphadenitis and to identify the caus-ative bacteria

2 Materials and Methods

21 StudyAreaandAnimals e study was conducted at theon-station Boertimes Central Highland Goat cross-breedingprogram carried out at Ataye Research site Debre BirhanAgricultural Research Center Ethiopia e site is located incentral Ethiopia and the climate is characterized by bimodalrainfall consisting of the long rainy season (June-Septem-ber) short rainy season (February-May) and dry season(October-January) [13] e sitersquos geographic coordinatereference is 10deg35prime N latitude and 39deg93prime E longitude and islocated at 1491m above sea level altitude (Figure 1)

e study animals were a mix of different goat breedgroups including Boer Boer cross with Central HighlandGoat and Central Highland Goats e flock was managedsemi-intensively with grazing and supplement e sup-plement includes ad libitum grass hay chopped pasture(Napier grass Desmodium spp and vetch) and concen-trated supplement based on their body weight Detailsummary of breeding feeding management system anddata recording of the flock are presented in [14 15]

22 Clinical Examination and Sample Collection e studywas carried out on a goat farm maintained under a semi-intensive system in the lowland of North Shoa AtayeDistrict Ethiopia e study was conducted over a period of8 years (June 2011 to January 2019) using a longitudinal(both retrospective and prospective) follow-up study designA total of 1025 goats of breeds 287 Boer goat 515BoertimesCHG and 223 CHG) were followed up and clinicallyexamined for the presence of enlarged and abscessed su-perficial lymph nodes and internal caseous abscess duringpostmortem examination Pus samples from 32 goats withlesions suspected of caseous lymphadenitis were taken aftershaved and disinfected with 70 alcohol or savlon and then

an incision was made with a sterile blade and the sampleswere transported in icebox to the microbiology laboratory ofDebre Birhan Agricultural Research Center

23 Descriptive Statistics and Survival Analysis Data col-lected from clinical cases and laboratory tests were enteredinto an Excel spreadsheet Clinical records were rearrangedas time-to-event data form in the Excel spreadsheet estarting point of follow-up was the date (daymonthyearformat) that the goat joined the farm through birth pur-chase or transfer from other research centers e eventfailure time was the date (daymonthyear format) a goatshows CLA clinical signSince the disease is characterized bya recurrent relapse of abscess due to poor response to an-tibiotic treatment the data were rearranged according to thecounting process data layout with multiple observations persubject [16] Goats that fail in the first time will be againrecorded using the first failure time as the initial timeCensored observations are goats that leave out the farm bydeath (the most common one) by transfer or end of thestudy period

e estimation of the survivor function was computed asfollows [17]

1113954S(t) 1113945j tjlet

1 minusdj

nj

1113888 1113889 (1)

where S (t) is the value of survival function at a time tj nj isthe number of goats without caseous lymphadenitis cases attime tj and dj is the number of goats with caseouslymphadenitis cases at time tj Survival curves were con-structed with the KaplanndashMeier method and we used thesurvival curve plotting macro NEWSURV [18]

e risk factors associated with caseous lymphadenitiswere assessed using multivariate Cox regression analysisadjusted for sex age breed season and year Statisticalanalyses were performed using SAS statistical softwareversion 94 [19] We used the PROC PHREG option calledCOVSANDWICH that corrects for the dependence of re-peated events on the same goat over time is option in-vokes a method variously known as the robust varianceestimator or the modified sandwich estimator developed forCox regression by Allison [16] and Lin and Wei [20] eproportional hazard assumption of covariates was checkedusing PH ASSES option and for the violated variables weadd time interaction in the model Year when the goat joinedthe farm was used as a stratifying variable p values lt005were considered as statistically significant en Weibullproportional hazard model for the caseous lymphadenitiscase of a particular goat at a time (t) was designed as follows

λ(t) λ0 (t)lowast exp Agei + Sexj + Seasonk1113872 1113873 (2)

where λ (t) is the risk of caseous lymphadenitis or probabilityof goats being caseous lymphadenitis positive at time t λ0 (t)is the baseline hazard function with shape parameter p andscale parameter λ of the Weibull distribution or λ0 (t) λρ(λt)pminus1 Agei is fixed effect of the ith age of goat when joinedthe farm Sexj is fixed effect of the jth sex of goat and Seasonk

2 Veterinary Medicine International

is fixed effect of the kth season of the year when the goatjoined the farm

24 Bacteriological and Biolog MicroStation with GEN IIIMicroplate System Bacteria Rapid Identificationirty-two pus samples taken from suspected caseouslymphadenitis abscess were cultured on 7 sheep blood agarfor 48ndash72 h at 37degC and bacterial colonies were identified onthe basis of morphological characteristics biochemical testsie catalase urease trehalose xylose maltose and glucosefermentation tests and reverse CAMP test (antagonistichaemolysis between Corynebacterium pseudotuberculosisand Staphylococcus aureus) for phospholipase D (PLD)production [4] Catalase PLD and urease-positive andnitrate-negative cultures were considered positive forC pseudotuberculosis

Out of 32 bacterial cultures 12 samples of well-grownbacterial colonies on blood agar were transported to theNational Animal Health Diagnostic Center Sebeta in iceboxfor further bacterial species identification OmniLog (fullyautomated coated microplate-based bacterial identificationsystem) that is GEN III microplate with protocol Amethodwas used to test suspected colonies A single colony grownon Biolog Universal Growth (BUG) agar medium was se-lected and emulsified into ldquoinoculating fluid Ardquo (IF A)

According to the manufacturerrsquos instructions cell density ofthe bacterial inoculum was measured for a specifiedtransmittance (90 to 98) using a turbid meter as specifiedin the user guide For each isolate 100 μl of the cell sus-pension was inoculated into each of the 96-well coatedmicroplate using an automatic multichannel pipette andincubated aerobically at 33degC for 22 h e OmniLogidentification system automatically reads each microplateand provides identification called speciessubspecies ID andthen the results were printed (GEN III database version5201) e results were also read in the Biolog MicroStationreader after 22 h incubation outside GEN III incubation

3 Results

31 Descriptive Statistics and Survival Analysis During theoverall eight-year clinical follow-up study period out of1025 goats examined we found 214 abscess cases clinicallydiagnosed as caseous lymphadenitis (Figures 2(a) and 2(b))In the recurrent survival data analysis there were 1 138observations and 214 cases (812 of goats with a prevalenceof 188 were censored due to mortality transfer to otherplaces or end of the study period) and the incidence rate was014 cases per animal year e prevalence was highest inBoertimesCHG goats (2103) From a total of 214 cases 130have occurred once and they did not relapse and 84 cases are

10deg40prime0PrimeN

10deg30prime0PrimeN

10deg20prime0PrimeN

10deg10prime0PrimeN

10deg0prime0PrimeN

9deg50prime0PrimeN

9deg40prime0PrimeN

9deg30prime0PrimeN

9deg20prime0PrimeN

9deg10prime0PrimeN

9deg0prime0PrimeN

8deg50prime0PrimeN

8deg40prime0PrimeN

Efeson townRoadsRivers

Efrata ena gedmNorth Shoa

38deg30prime0PrimeE 38deg50prime0PrimeE 38deg10prime0PrimeE 39deg30prime0PrimeE 39deg50prime0PrimeE 40deg10prime0PrimeE

Figure 1 Map of Ethiopia showing the region zone district and town where the study site is located

Veterinary Medicine International 3

twice or more relapse cases (Table 1) e incidence rate was014 cases per animal year

e most frequent cases occurred on the head regionlymph node of the parotid (92 (4299 relative percent)cases) prescapular (36 (1682)) and prefemoral (23(1075)) and the least frequent sites were the supra-mammary (234) cervical (187) and visceral organs(liver and lung) (187) (Table 2)

e typical clinical lesion is small and firm swelling ofexternal lymph nodes of different locations (Figure 2(a))e abscess is enclosed in a well-circumscribed fibrous tissueand when incised thick and often dry greyish or whitepurulent exudates Cut section of some of the affected lymphnodes revealed a characteristic onion-like appearance(Figure 2(b))

e unadjusted KaplanndashMeier survival function curvefrom birth or entry to farm to 60 months of the follow-upperiod of caseous lymphadenitis stratified based on the breedof goat season and age when the goat joined the farmindicates that the failure rate is steady and the mediansurvival time is around 565 months (46 years) (Figure 3(d))

ere was a significant difference between breed season andage (Figure 3) Newborn kid starts clinical cases by around 6

months of age and the failure rate is steady reaching theirmedian survival time at 368months (nearly 3 years old)(Figure 3(b)) At the end of the study the cumulative failurerates were 68 for newborn and 64 for yearlings ehazard is higher for newborn goats starting from first yearinterval up to the end while the hazard is relatively lower inthe first three years for yearling goats and higher after threeyears of age (Table 3) e survival rate is poor for Boer crosswith local Central Highland Goat and goats joined the farmduring the dry season (Figures 3(a) and 3(c))

Proportional hazard regression analysis of risk factorsusing the robust variance analysis of recurrent events andyear as a stratifying variable showed that age sex and breedwere associated with (p valuelt 005) caseous lymphadenitisoccurrence (survival) and season of the year when the goatjoined the farm was not associated with caseous lymphad-enitis survival Newborn goats compared with yearling agegoats have 4801 times higher probability of being infectedwith caseous lymphadenitis (p valuelt 00001) Female goats

(a) (b)

(c) (d)

Figure 2 Images of CLA prescapular LN case (a) incised retropharyngeal LN case (b) sample culture on blood agar (c) and Gram stain ofthe bacteria (d)

Table 1 Summary of caseous lymphadenitis cases with order of recurrence

Caseous lymphadenitis casesBreed N Positive () 1st case 2nd case 3rd case 4th case 5th case 6th caseBoer goat 314 53 (1688) 34 12 4 2 1 0BoertimesCHG 585 123 (2103) 72 28 11 7 4 1CHG 239 38 (159) 24 9 3 2 0 0Total 1138 214 (1880) 130 49 18 11 5 1Note CHG Central Highland Goat

4 Veterinary Medicine International

have 1856 times higher rate of being infected compared withmale goats (p value 00023) Pure Boer goat breeds have4217 times higher rate of being infected (p valuelt 00001)and Boer cross with Central Highland Goat breeds have4562 times higher rate of being infected (p value lt 00001)compared with local Central Highland Goat Breed goats(Table 4)

32 Bacteriological and Biolog MicroStation with GEN IIIMicroplate System Results From 32 pus samples of CLAsuspected goats we were able to recover pure colonies ofbacteria (Figure 2(c)) All of the samples were found to bepositive for C pseudotuberculosis based on cultural exam-ination All isolates of C pseudotuberculosis were Gram-positive pleomorphic rod (Figure 2(d)) catalase-positiveurease-positive antagonistic haemolysis with Staphylococcusaureus for phospholipase D (PLD) production and nitrate-negative [4] Out of 12 bacterial cultures tested using BiologMicroStation with GEN III microplate system results 10were C pseudotuberculosis and 2 of them were C ulcerans

4 Discussions

41 Descriptive Statistics and Survival Analysis e presentstudy shows the prevalence of CLA as 188 and the in-cidence rate as 014 cases per animal year e cumulativefailure rates were 68 for newborn aged goats and 64 foryearling aged goats is result indicates a high rate of CLAinfection rate at Ataye goat farm e cases were charac-terized by poor response to local and systemic antibiotictreatments e farm veterinarians cost a considerable timeto treat the frequent cases including the recurrent abscessfollowing incision local treatment by iodine and savlonand systemic antibiotic treatments using long-actingoxytetracycline

e current prevalence is in line with reports abroad1923 prevalence by Al-Gaabary et al [21] 26 preva-lence by Paton [22] and in Ethiopia 15 by Fikre andAbraha [10] e current port is relatively higher than mostreports in Ethiopia 47 by Molla [12] 117 by Abebe andSisay [23] and 10 by Hunduma et al [11] e variations

in the disease frequency between different studies may beattributed to the differences in the management systemsand climatic conditions in each study where the viability ofthe causative organism in the contaminated environment isgreatly affected by ambient temperature and it may also beattributed to the endemic nature of the disease which leadsto a variation in animal immunity and the degree of animalsusceptibility [21] In Australia the prevalence of CLA haddecreased from over 50 in the 1770s to approximately20 in the late 1990s through the use of recommendedCLA vaccine [22 24] e higher rate of infection in ourstudy was due to semi-intensive management of goats ahigher density of flocks on the smaller grazing land higherdensity at the barn and the lower quarantine practice ofclinical cases in the farm where all of them aggravates thetransmission rare of the disease ere is also no vaccineavailable in the country

e most affected superficial lymph node was theparotid lymph node Similar results were reported in[2 10] ese results may be attributed to the habit ofgoats that tend to scratch their shoulders and headsagainst walls and fences or any hard objects resulting in ahigh percentage of superficial parotid mandibular cer-vical and prefemoral lymph node infection because itdrains the shoulder region [10]

e hazard of CLA was higher (plt 0001) in the new-born than in the yearling age group is result contradictsfrom other findings [10 21] where age groups below 1 yearare at a lower riskis may be due to variation in the type ofstudy and age classification method In this result new casesare started at around 6 months of age e higher incidencerate in the newborn is due to the poor immunity of kids

Female goats were at higher (plt 00023) risk of infectionthan male goats Similar reports indicated a higher preva-lence of CLA in female groups [21 25] ese results may beattributed to the fact that does usually reared for older agesthan bucks as well as a relatively higher number of doesusually reared in one group resulting in a high rate ofcontact However a fewer number of males are kept togethermainly for the mating purpose of the farm [14 15]

Breed variation was the other important risk factor in theproportional hazard analysis Boer and Boer cross with local

Table 2 Summary of caseous lymphadenitis cases with lymph node location

Goat breedCLA location Boer goat BoertimesCHG CHG Total (relative )Parotid LN 21 55 16 92 (4299)Prescapular LN 10 21 5 36 (1682)Prefemoral LN 2 13 8 23 (1075)Undefined LN 2 12 0 14 (654)Mandibular LN 3 4 4 11 (514)Pharyngeal LN 4 7 0 11 (514)Multiple LNs 2 7 0 9 (421)Skin area 1 2 2 5 (234)Supramammary LN 2 1 2 5 (234)Cervical LN 3 1 0 4 (187)Visceral organs LN 3 0 1 4 (187)Overall cases N () 53314 (1688) 123585 (2103) 38239 (1590) 2141138 (1880)Note CHG Central Highland Goat CLA caseous lymphadenitis LN lymph node

Veterinary Medicine International 5

Central Highland Goats were at higher risk (plt 00001)compared with the local Central Highland Goat breedsGenerally the imported Boer goats are at higher risk tovarious disease conditions [26] is may be due to thehigher resistance of local breeds due to adaptation [12]

42 Bacteriological and Biolog MicroStation with GEN IIIMicroplate System Results We recovered 32C pseudotuberculosis bacteria from all 32 cultured abscesssamples From 12 pure culture samples tested using the Biolog-based test 10 of themwere C pseudotuberculosis and 2 of themwere C ulcerans positive However all of the 12 samples wereC pseudotuberculosis positive based on the biochemical testmethod e Biolog-based test screened the 2 samples as Culcerans e current result is in line with most previous

findings C pseudotuberculosis were the most frequent isolatedbacteria of clinical CLA abscess [10 21 23 25 27]e presentresult of 2 C ulcerans based on the Biolog test is the first reportin Ethiopia Although the differentiation between C ulceransand C pseudotuberculosis was based on a single biochemicalreaction the trehalose test the present results are in agreementwith previous studies [28] and indicate that the microorganismisolated in the present study was C ulcerans ere are alsoreports indicating that C ulcerans was isolated from clinicalcases of goat [29] C ulcerans is an emerging zoonotic diseasethat causes diphtheria like illness in humans [30 31]

5 Conclusion and Recommendations

Clinical and bacteriological study of the caseous lymphad-enitis indicates that the high prevalence of caseous

Breed Total Event Median (95 CI)Boer goat 314 53 650 (544-NE)Boer x CHG 585 123 368 (327-497)CHG 239 38 NE (565-NE)

10095

85

75

65

55

45

35

250 10 20 30

Goat age (months)

Surv

ival

(per

cent

age)

40 50 60

(a)

10095

85

75

65

55

45

35

250 10 20 30

Goat age (months)

Surv

ival

(per

cent

age)

40 50 60

Age Total Event Median (95 CI)764 145 368 (333-497)Newborn

Yearling 374 69 845 (600-NE)

(b)100

95

85

75

65

55

45

35

250 10 20 30

Goat age (months)

Surv

ival

(per

cent

age)

40 50 60

Total Event Median (95 CI)Season399 78 315 (260-NE)379 89 497 (460-692)

DryShort rainySummer 363 47 845 (668-NE)

(c)

10095

85

75

65

55

45

35

25

0 12 186 24 30 36Goat age (months)

Surv

ival

(per

cent

age)

42 48 54 60

Total Event

No at risk1138 613 519 293 108 48

Median (95 CI)1138 214 565 (508-692)

(d)

Figure 3 KaplanndashMeier survival function curve of caseous lymphadenitis cases from birth or entry to farm to 60 months of the follow-upperiod

6 Veterinary Medicine International

lymphadenitis in this goat farm Moreover repeated abscessoccurs after treatment Laboratory work reveals that Cpseudotuberculosis and C ulcerans were isolated bacteriathat cause abscess disease us the frequent abscess aftertreatment indicates poor response of the disease to differentantibiotics and antiseptic chemicals Control and preventionin sheep and goat farms should focus on quarantine andculling of positive animals and vaccination with the CLAvaccine

Data Availability

e datasets used to support the findings of this study areavailable from the corresponding author upon request

Conflicts of Interest

e authors declare that there are no conflicts of interestregarding the publication of this paper

Acknowledgments

is study was supported by Amhara Regional AgriculturalResearch Center (LsAhSh13DB-201518)

References

[1] S Ivanovic M Zutic I Pavlovic and M Zujovic ldquoCaseouslymphadenitis in goatsrdquo Biotechnology in Animal Husbandryvol 25 no 5-6-2 pp 999ndash1007 2009

[2] L H Williamson ldquoCaseous lymphadenitis in small rumi-nantsrdquo Veterinary Clinics of North America Food AnimalPractice vol 17 no 2 pp 359ndash371 2001

[3] G J Baird and M C Fontaine ldquoCorynebacterium pseudotu-berculosis and its role in ovine caseous lymphadenitisrdquo Journal ofComparative Pathology vol 137 no 4 pp 179ndash210 2007

[4] P Quin M Carter B Markey and E Carter ldquoCorynebac-terium species and Rhodococcus equirdquo in Clinical VeterinaryMicrobiology pp 137ndash143 Elsevier London UK 2004

[5] G J Baird and F E Malone ldquoControl of caseous lymph-adenitis in six sheep flocks using clinical examination andregular ELISA testingrdquo Veterinary Record vol 166 no 12pp 358ndash362 2010

[6] D P Dercksen J M A Brinkhof T Dekker-Nooren et al ldquoAcomparison of four serological tests for the diagnosis of ca-seous lymphadenitis in sheep and goatsrdquo Veterinary Micro-biology vol 75 no 2 pp 167ndash175 2000

[7] F A Dorella L Carvalho Pacheco S C Oliveira A Miyoshiand V Azevedo ldquoCorynebacterium pseudotuberculosismicrobiology biochemical properties pathogenesis andmolecular studies of virulencerdquo Veterinary Research vol 37no 2 pp 201ndash218 2006

Table 4 Proportional hazard regression analysis results of explanatory variables effect on caseous lymphadenitis with robust standarderrors

Variables Parameter estimate Standard error St err ratio HR 95 HR CI p valueAge Newborn vs yearling 156880 029319 0827 4801 [2702ndash8529] lt00001Sex Female vs male 061824 020285 1159 1856 [1247ndash2762] 00023

Breed Boer vs CHG 143907 022716 0657 4217 [2702ndash6582] lt00001BoertimesCHG vs CHG 151778 037440 0912 4562 [2190ndash9503] lt00001

Season Summer vs short rain 019403 029058 1208 1214 [0687ndash2146] 05043Dry vs short rain 004796 017486 0948 1049 [0745ndash1478] 07839

Note CI confidence interval St err standard error HR hazard ratio CHG Central Highland Goat

Table 3 Life table of CLA cases stratified based on the age of goats

Age groupInterval(months) Total Cases Lost Cumulative failures Hazard

95 CI hazardLower Upper

Newborn

0 12 764 61 439 011 0010 0007 001212 24 264 48 80 030 0020 0014 002624 36 136 21 53 044 0018 0010 002536 48 62 9 17 053 0015 0005 002548 60 36 5 22 062 0019 0002 003560 72 9 1 4 068 0013 0000 003872 84 4 0 4 068 0000

Yearling

0 12 374 16 103 005 0004 0002 000612 24 255 16 82 012 0007 0003 001024 36 157 4 33 015 0002 0000 000536 48 120 15 33 027 0013 0007 002048 60 72 11 22 040 0017 0007 002660 72 39 3 13 046 0008 0000 001772 84 23 1 6 048 0004 0000 001384 96 16 3 12 064 0029 0000 006296 108 1 0 1 064 0000

Veterinary Medicine International 7

[8] J Arsenault C Girard P Dubreuil et al ldquoPrevalence of andcarcass condemnation from maedi-visna paratuberculosisand caseous lymphadenitis in culled sheep from QuebecCanadardquo Preventive Veterinary Medicine vol 59 no 1-2pp 67ndash81 2003

[9] M W Paton A R Mercy F C Wilkinson J J GardnerS S Sutherland and T M Ellis ldquoe effects of caseouslymphadenitis on wool production and bodyweight in youngsheeprdquo Australian Veterinary Journal vol 65 no 4pp 117ndash119 1988

[10] Z Fikre and G K Abraha ldquoCaseous lymphadenitis in goatsfrom Borena Range land south Ethiopia slaughtered at Lunaexport abattoirrdquo Journal of Veterinary Medicine and AnimalHealth vol 6 no 6 pp 168ndash173 2014

[11] D Hunduma W Tigre M Wagari and F Regassa ldquoPre-liminary study on major health problems of the newly in-troduced Boer goat breed in EthiopiardquoWorld Applied SciencesJournal vol 11 no 7 pp 803ndash807 2010

[12] B Molla ldquoe health performance of imported Boer goat(Capra hircus) and their crosses with Woito-guji goat breedsin South Omo Zone South-Western Ethiopiardquo TropicalAnimal Health and Production vol 48 no 4 pp 855ndash8612016

[13] K Fekadu ldquoEthiopian seasonal rainfall variability and pre-diction using canonical correlation analysis (CCA)rdquo EarthSciences vol 4 no 3 pp 112ndash119 2015

[14] A Mustefa ldquoReproduction and survival analysis of Boer andtheir crosses with Central Highland goats in EthiopiardquoLivestock Research for Rural Development vol 31 no 10 2019

[15] A Mustefa S Gizaw S Banerjee and A Abebe ldquoGrowthperformance of Boer goats and their F1 and F2 crosses andbackcrosses with central highland goats in Ethiopiardquo LivestockResearch for Rural Development vol 31 no 6 2019

[16] P D Allison Survival Analysis Using SAS A Practical GuideSAS Institute Cary NC USA 2010

[17] E L Kaplan and P Meier ldquoNonparametric estimation fromincomplete observationsrdquo Journal of the American StatisticalAssociation vol 53 no 282 pp 457ndash481 1958

[18] J Meyers ldquoe NEWSURV family of macros an update onthe survival plotting macroNEWSURV and an introductionto expansion macrosrdquo in Proceedings of the Pharma SUG2017 pp 14ndash17 Rochester MN USA 2017

[19] SAS Base SAS 94 Procedures Guide SAS Institute Inc CaryNC USA 94 edition 2015

[20] D Y Lin and L J Wei ldquoe robust inference for the coxproportional hazards modelrdquo Journal of the American Sta-tistical Association vol 84 no 408 pp 1074ndash1078 1989

[21] M H Al-Gaabary S A Osman and A F Oreiby ldquoCaseouslymphadenitis in sheep and goats clinical epidemiologicaland preventive studiesrdquo Small Ruminant Research vol 87no 1ndash3 pp 116ndash121 2009

[22] M W Paton S B Walker I R Rose and G F WattldquoPrevalence of caseous lymphadenitis and usage of caseouslymphadenitis vaccines in sheep flocksrdquo Australian Veteri-nary Journal vol 81 no 1-2 pp 91ndash95 2003

[23] D Abebe and T Sisay Tessema ldquoDetermination ofCor-ynebacterium pseudotuberculosisprevalence and antimicro-bial susceptibility pattern of isolates from lymph nodes ofsheep and goats at an organic export abattoir ModjoEthiopiardquo Letters in Applied Microbiology vol 61 no 5pp 469ndash476 2015

[24] P W Michael ldquoe epidemiology and control of caseouslymphadenitis in Australian sheep flocksrdquo in PhD School of

Veterinary and Biomedical Sciences Murdoch UniversityMurdoch Australia 2010

[25] R Ghanbarpour and M Khaleghiyan ldquoA study on caseouslymphadenitis in goatsrdquo Indian Veterinary Journal vol 82pp 1013-1014 2005

[26] E Alemnew E Yitagesu H Addis and A Areaya ldquoRetro-spective epidemiological study on goat disease in Debrebirhan agricultural Research center Ataye boer breedingevaluation and distribution site North Shoa EthiopiardquoBiomedicine and Nursing vol 6 no 1 pp 1ndash10 2020

[27] M H Al-Gaabary S A Osman M S Ahmed andA F Oreiby ldquoAbattoir survey on caseous lymphadenitis insheep and goats in Tanta Egyptrdquo Small Ruminant Researchvol 94 no 1ndash3 pp 117ndash124 2010

[28] B Ccediletinkaya M Karahan E Atil R Kalin T De Baere andM Vaneechoutte ldquoIdentification of Corynebacterium pseu-dotuberculosis isolates from sheep and goats by PCRrdquo Vet-erinary Microbiology vol 88 no 1 pp 75ndash83 2002

[29] W Morris F A Uzal and A Cipolla PyogranulomatousMeningoencephalitis in a Goat Due to CorynebacteriumUlcerans British Medical Journal Publishing Group LondonUK 2005

[30] T S P Tiwari A Golaz D T Yu et al ldquoInvestigations of 2cases of diphtheria-like illness due to toxigenic Corynebac-terium ulceransrdquo Clinical Infectious Diseases vol 46 no 3pp 395ndash401 2008

[31] D Weerasekera Characterization of Virulence Factors ofCorynebacterium Diphtheriae and Corynebacterium UlceransFriedrich-Alexander-Universitat Erlangen-Nurnberg (FAU)Erlangen Germany 2019

8 Veterinary Medicine International

is fixed effect of the kth season of the year when the goatjoined the farm

24 Bacteriological and Biolog MicroStation with GEN IIIMicroplate System Bacteria Rapid Identificationirty-two pus samples taken from suspected caseouslymphadenitis abscess were cultured on 7 sheep blood agarfor 48ndash72 h at 37degC and bacterial colonies were identified onthe basis of morphological characteristics biochemical testsie catalase urease trehalose xylose maltose and glucosefermentation tests and reverse CAMP test (antagonistichaemolysis between Corynebacterium pseudotuberculosisand Staphylococcus aureus) for phospholipase D (PLD)production [4] Catalase PLD and urease-positive andnitrate-negative cultures were considered positive forC pseudotuberculosis

Out of 32 bacterial cultures 12 samples of well-grownbacterial colonies on blood agar were transported to theNational Animal Health Diagnostic Center Sebeta in iceboxfor further bacterial species identification OmniLog (fullyautomated coated microplate-based bacterial identificationsystem) that is GEN III microplate with protocol Amethodwas used to test suspected colonies A single colony grownon Biolog Universal Growth (BUG) agar medium was se-lected and emulsified into ldquoinoculating fluid Ardquo (IF A)

According to the manufacturerrsquos instructions cell density ofthe bacterial inoculum was measured for a specifiedtransmittance (90 to 98) using a turbid meter as specifiedin the user guide For each isolate 100 μl of the cell sus-pension was inoculated into each of the 96-well coatedmicroplate using an automatic multichannel pipette andincubated aerobically at 33degC for 22 h e OmniLogidentification system automatically reads each microplateand provides identification called speciessubspecies ID andthen the results were printed (GEN III database version5201) e results were also read in the Biolog MicroStationreader after 22 h incubation outside GEN III incubation

3 Results

31 Descriptive Statistics and Survival Analysis During theoverall eight-year clinical follow-up study period out of1025 goats examined we found 214 abscess cases clinicallydiagnosed as caseous lymphadenitis (Figures 2(a) and 2(b))In the recurrent survival data analysis there were 1 138observations and 214 cases (812 of goats with a prevalenceof 188 were censored due to mortality transfer to otherplaces or end of the study period) and the incidence rate was014 cases per animal year e prevalence was highest inBoertimesCHG goats (2103) From a total of 214 cases 130have occurred once and they did not relapse and 84 cases are

10deg40prime0PrimeN

10deg30prime0PrimeN

10deg20prime0PrimeN

10deg10prime0PrimeN

10deg0prime0PrimeN

9deg50prime0PrimeN

9deg40prime0PrimeN

9deg30prime0PrimeN

9deg20prime0PrimeN

9deg10prime0PrimeN

9deg0prime0PrimeN

8deg50prime0PrimeN

8deg40prime0PrimeN

Efeson townRoadsRivers

Efrata ena gedmNorth Shoa

38deg30prime0PrimeE 38deg50prime0PrimeE 38deg10prime0PrimeE 39deg30prime0PrimeE 39deg50prime0PrimeE 40deg10prime0PrimeE

Figure 1 Map of Ethiopia showing the region zone district and town where the study site is located

Veterinary Medicine International 3

twice or more relapse cases (Table 1) e incidence rate was014 cases per animal year

e most frequent cases occurred on the head regionlymph node of the parotid (92 (4299 relative percent)cases) prescapular (36 (1682)) and prefemoral (23(1075)) and the least frequent sites were the supra-mammary (234) cervical (187) and visceral organs(liver and lung) (187) (Table 2)

e typical clinical lesion is small and firm swelling ofexternal lymph nodes of different locations (Figure 2(a))e abscess is enclosed in a well-circumscribed fibrous tissueand when incised thick and often dry greyish or whitepurulent exudates Cut section of some of the affected lymphnodes revealed a characteristic onion-like appearance(Figure 2(b))

e unadjusted KaplanndashMeier survival function curvefrom birth or entry to farm to 60 months of the follow-upperiod of caseous lymphadenitis stratified based on the breedof goat season and age when the goat joined the farmindicates that the failure rate is steady and the mediansurvival time is around 565 months (46 years) (Figure 3(d))

ere was a significant difference between breed season andage (Figure 3) Newborn kid starts clinical cases by around 6

months of age and the failure rate is steady reaching theirmedian survival time at 368months (nearly 3 years old)(Figure 3(b)) At the end of the study the cumulative failurerates were 68 for newborn and 64 for yearlings ehazard is higher for newborn goats starting from first yearinterval up to the end while the hazard is relatively lower inthe first three years for yearling goats and higher after threeyears of age (Table 3) e survival rate is poor for Boer crosswith local Central Highland Goat and goats joined the farmduring the dry season (Figures 3(a) and 3(c))

Proportional hazard regression analysis of risk factorsusing the robust variance analysis of recurrent events andyear as a stratifying variable showed that age sex and breedwere associated with (p valuelt 005) caseous lymphadenitisoccurrence (survival) and season of the year when the goatjoined the farm was not associated with caseous lymphad-enitis survival Newborn goats compared with yearling agegoats have 4801 times higher probability of being infectedwith caseous lymphadenitis (p valuelt 00001) Female goats

(a) (b)

(c) (d)

Figure 2 Images of CLA prescapular LN case (a) incised retropharyngeal LN case (b) sample culture on blood agar (c) and Gram stain ofthe bacteria (d)

Table 1 Summary of caseous lymphadenitis cases with order of recurrence

Caseous lymphadenitis casesBreed N Positive () 1st case 2nd case 3rd case 4th case 5th case 6th caseBoer goat 314 53 (1688) 34 12 4 2 1 0BoertimesCHG 585 123 (2103) 72 28 11 7 4 1CHG 239 38 (159) 24 9 3 2 0 0Total 1138 214 (1880) 130 49 18 11 5 1Note CHG Central Highland Goat

4 Veterinary Medicine International

have 1856 times higher rate of being infected compared withmale goats (p value 00023) Pure Boer goat breeds have4217 times higher rate of being infected (p valuelt 00001)and Boer cross with Central Highland Goat breeds have4562 times higher rate of being infected (p value lt 00001)compared with local Central Highland Goat Breed goats(Table 4)

32 Bacteriological and Biolog MicroStation with GEN IIIMicroplate System Results From 32 pus samples of CLAsuspected goats we were able to recover pure colonies ofbacteria (Figure 2(c)) All of the samples were found to bepositive for C pseudotuberculosis based on cultural exam-ination All isolates of C pseudotuberculosis were Gram-positive pleomorphic rod (Figure 2(d)) catalase-positiveurease-positive antagonistic haemolysis with Staphylococcusaureus for phospholipase D (PLD) production and nitrate-negative [4] Out of 12 bacterial cultures tested using BiologMicroStation with GEN III microplate system results 10were C pseudotuberculosis and 2 of them were C ulcerans

4 Discussions

41 Descriptive Statistics and Survival Analysis e presentstudy shows the prevalence of CLA as 188 and the in-cidence rate as 014 cases per animal year e cumulativefailure rates were 68 for newborn aged goats and 64 foryearling aged goats is result indicates a high rate of CLAinfection rate at Ataye goat farm e cases were charac-terized by poor response to local and systemic antibiotictreatments e farm veterinarians cost a considerable timeto treat the frequent cases including the recurrent abscessfollowing incision local treatment by iodine and savlonand systemic antibiotic treatments using long-actingoxytetracycline

e current prevalence is in line with reports abroad1923 prevalence by Al-Gaabary et al [21] 26 preva-lence by Paton [22] and in Ethiopia 15 by Fikre andAbraha [10] e current port is relatively higher than mostreports in Ethiopia 47 by Molla [12] 117 by Abebe andSisay [23] and 10 by Hunduma et al [11] e variations

in the disease frequency between different studies may beattributed to the differences in the management systemsand climatic conditions in each study where the viability ofthe causative organism in the contaminated environment isgreatly affected by ambient temperature and it may also beattributed to the endemic nature of the disease which leadsto a variation in animal immunity and the degree of animalsusceptibility [21] In Australia the prevalence of CLA haddecreased from over 50 in the 1770s to approximately20 in the late 1990s through the use of recommendedCLA vaccine [22 24] e higher rate of infection in ourstudy was due to semi-intensive management of goats ahigher density of flocks on the smaller grazing land higherdensity at the barn and the lower quarantine practice ofclinical cases in the farm where all of them aggravates thetransmission rare of the disease ere is also no vaccineavailable in the country

e most affected superficial lymph node was theparotid lymph node Similar results were reported in[2 10] ese results may be attributed to the habit ofgoats that tend to scratch their shoulders and headsagainst walls and fences or any hard objects resulting in ahigh percentage of superficial parotid mandibular cer-vical and prefemoral lymph node infection because itdrains the shoulder region [10]

e hazard of CLA was higher (plt 0001) in the new-born than in the yearling age group is result contradictsfrom other findings [10 21] where age groups below 1 yearare at a lower riskis may be due to variation in the type ofstudy and age classification method In this result new casesare started at around 6 months of age e higher incidencerate in the newborn is due to the poor immunity of kids

Female goats were at higher (plt 00023) risk of infectionthan male goats Similar reports indicated a higher preva-lence of CLA in female groups [21 25] ese results may beattributed to the fact that does usually reared for older agesthan bucks as well as a relatively higher number of doesusually reared in one group resulting in a high rate ofcontact However a fewer number of males are kept togethermainly for the mating purpose of the farm [14 15]

Breed variation was the other important risk factor in theproportional hazard analysis Boer and Boer cross with local

Table 2 Summary of caseous lymphadenitis cases with lymph node location

Goat breedCLA location Boer goat BoertimesCHG CHG Total (relative )Parotid LN 21 55 16 92 (4299)Prescapular LN 10 21 5 36 (1682)Prefemoral LN 2 13 8 23 (1075)Undefined LN 2 12 0 14 (654)Mandibular LN 3 4 4 11 (514)Pharyngeal LN 4 7 0 11 (514)Multiple LNs 2 7 0 9 (421)Skin area 1 2 2 5 (234)Supramammary LN 2 1 2 5 (234)Cervical LN 3 1 0 4 (187)Visceral organs LN 3 0 1 4 (187)Overall cases N () 53314 (1688) 123585 (2103) 38239 (1590) 2141138 (1880)Note CHG Central Highland Goat CLA caseous lymphadenitis LN lymph node

Veterinary Medicine International 5

Central Highland Goats were at higher risk (plt 00001)compared with the local Central Highland Goat breedsGenerally the imported Boer goats are at higher risk tovarious disease conditions [26] is may be due to thehigher resistance of local breeds due to adaptation [12]

42 Bacteriological and Biolog MicroStation with GEN IIIMicroplate System Results We recovered 32C pseudotuberculosis bacteria from all 32 cultured abscesssamples From 12 pure culture samples tested using the Biolog-based test 10 of themwere C pseudotuberculosis and 2 of themwere C ulcerans positive However all of the 12 samples wereC pseudotuberculosis positive based on the biochemical testmethod e Biolog-based test screened the 2 samples as Culcerans e current result is in line with most previous

findings C pseudotuberculosis were the most frequent isolatedbacteria of clinical CLA abscess [10 21 23 25 27]e presentresult of 2 C ulcerans based on the Biolog test is the first reportin Ethiopia Although the differentiation between C ulceransand C pseudotuberculosis was based on a single biochemicalreaction the trehalose test the present results are in agreementwith previous studies [28] and indicate that the microorganismisolated in the present study was C ulcerans ere are alsoreports indicating that C ulcerans was isolated from clinicalcases of goat [29] C ulcerans is an emerging zoonotic diseasethat causes diphtheria like illness in humans [30 31]

5 Conclusion and Recommendations

Clinical and bacteriological study of the caseous lymphad-enitis indicates that the high prevalence of caseous

Breed Total Event Median (95 CI)Boer goat 314 53 650 (544-NE)Boer x CHG 585 123 368 (327-497)CHG 239 38 NE (565-NE)

10095

85

75

65

55

45

35

250 10 20 30

Goat age (months)

Surv

ival

(per

cent

age)

40 50 60

(a)

10095

85

75

65

55

45

35

250 10 20 30

Goat age (months)

Surv

ival

(per

cent

age)

40 50 60

Age Total Event Median (95 CI)764 145 368 (333-497)Newborn

Yearling 374 69 845 (600-NE)

(b)100

95

85

75

65

55

45

35

250 10 20 30

Goat age (months)

Surv

ival

(per

cent

age)

40 50 60

Total Event Median (95 CI)Season399 78 315 (260-NE)379 89 497 (460-692)

DryShort rainySummer 363 47 845 (668-NE)

(c)

10095

85

75

65

55

45

35

25

0 12 186 24 30 36Goat age (months)

Surv

ival

(per

cent

age)

42 48 54 60

Total Event

No at risk1138 613 519 293 108 48

Median (95 CI)1138 214 565 (508-692)

(d)

Figure 3 KaplanndashMeier survival function curve of caseous lymphadenitis cases from birth or entry to farm to 60 months of the follow-upperiod

6 Veterinary Medicine International

lymphadenitis in this goat farm Moreover repeated abscessoccurs after treatment Laboratory work reveals that Cpseudotuberculosis and C ulcerans were isolated bacteriathat cause abscess disease us the frequent abscess aftertreatment indicates poor response of the disease to differentantibiotics and antiseptic chemicals Control and preventionin sheep and goat farms should focus on quarantine andculling of positive animals and vaccination with the CLAvaccine

Data Availability

e datasets used to support the findings of this study areavailable from the corresponding author upon request

Conflicts of Interest

e authors declare that there are no conflicts of interestregarding the publication of this paper

Acknowledgments

is study was supported by Amhara Regional AgriculturalResearch Center (LsAhSh13DB-201518)

References

[1] S Ivanovic M Zutic I Pavlovic and M Zujovic ldquoCaseouslymphadenitis in goatsrdquo Biotechnology in Animal Husbandryvol 25 no 5-6-2 pp 999ndash1007 2009

[2] L H Williamson ldquoCaseous lymphadenitis in small rumi-nantsrdquo Veterinary Clinics of North America Food AnimalPractice vol 17 no 2 pp 359ndash371 2001

[3] G J Baird and M C Fontaine ldquoCorynebacterium pseudotu-berculosis and its role in ovine caseous lymphadenitisrdquo Journal ofComparative Pathology vol 137 no 4 pp 179ndash210 2007

[4] P Quin M Carter B Markey and E Carter ldquoCorynebac-terium species and Rhodococcus equirdquo in Clinical VeterinaryMicrobiology pp 137ndash143 Elsevier London UK 2004

[5] G J Baird and F E Malone ldquoControl of caseous lymph-adenitis in six sheep flocks using clinical examination andregular ELISA testingrdquo Veterinary Record vol 166 no 12pp 358ndash362 2010

[6] D P Dercksen J M A Brinkhof T Dekker-Nooren et al ldquoAcomparison of four serological tests for the diagnosis of ca-seous lymphadenitis in sheep and goatsrdquo Veterinary Micro-biology vol 75 no 2 pp 167ndash175 2000

[7] F A Dorella L Carvalho Pacheco S C Oliveira A Miyoshiand V Azevedo ldquoCorynebacterium pseudotuberculosismicrobiology biochemical properties pathogenesis andmolecular studies of virulencerdquo Veterinary Research vol 37no 2 pp 201ndash218 2006

Table 4 Proportional hazard regression analysis results of explanatory variables effect on caseous lymphadenitis with robust standarderrors

Variables Parameter estimate Standard error St err ratio HR 95 HR CI p valueAge Newborn vs yearling 156880 029319 0827 4801 [2702ndash8529] lt00001Sex Female vs male 061824 020285 1159 1856 [1247ndash2762] 00023

Breed Boer vs CHG 143907 022716 0657 4217 [2702ndash6582] lt00001BoertimesCHG vs CHG 151778 037440 0912 4562 [2190ndash9503] lt00001

Season Summer vs short rain 019403 029058 1208 1214 [0687ndash2146] 05043Dry vs short rain 004796 017486 0948 1049 [0745ndash1478] 07839

Note CI confidence interval St err standard error HR hazard ratio CHG Central Highland Goat

Table 3 Life table of CLA cases stratified based on the age of goats

Age groupInterval(months) Total Cases Lost Cumulative failures Hazard

95 CI hazardLower Upper

Newborn

0 12 764 61 439 011 0010 0007 001212 24 264 48 80 030 0020 0014 002624 36 136 21 53 044 0018 0010 002536 48 62 9 17 053 0015 0005 002548 60 36 5 22 062 0019 0002 003560 72 9 1 4 068 0013 0000 003872 84 4 0 4 068 0000

Yearling

0 12 374 16 103 005 0004 0002 000612 24 255 16 82 012 0007 0003 001024 36 157 4 33 015 0002 0000 000536 48 120 15 33 027 0013 0007 002048 60 72 11 22 040 0017 0007 002660 72 39 3 13 046 0008 0000 001772 84 23 1 6 048 0004 0000 001384 96 16 3 12 064 0029 0000 006296 108 1 0 1 064 0000

Veterinary Medicine International 7

[8] J Arsenault C Girard P Dubreuil et al ldquoPrevalence of andcarcass condemnation from maedi-visna paratuberculosisand caseous lymphadenitis in culled sheep from QuebecCanadardquo Preventive Veterinary Medicine vol 59 no 1-2pp 67ndash81 2003

[9] M W Paton A R Mercy F C Wilkinson J J GardnerS S Sutherland and T M Ellis ldquoe effects of caseouslymphadenitis on wool production and bodyweight in youngsheeprdquo Australian Veterinary Journal vol 65 no 4pp 117ndash119 1988

[10] Z Fikre and G K Abraha ldquoCaseous lymphadenitis in goatsfrom Borena Range land south Ethiopia slaughtered at Lunaexport abattoirrdquo Journal of Veterinary Medicine and AnimalHealth vol 6 no 6 pp 168ndash173 2014

[11] D Hunduma W Tigre M Wagari and F Regassa ldquoPre-liminary study on major health problems of the newly in-troduced Boer goat breed in EthiopiardquoWorld Applied SciencesJournal vol 11 no 7 pp 803ndash807 2010

[12] B Molla ldquoe health performance of imported Boer goat(Capra hircus) and their crosses with Woito-guji goat breedsin South Omo Zone South-Western Ethiopiardquo TropicalAnimal Health and Production vol 48 no 4 pp 855ndash8612016

[13] K Fekadu ldquoEthiopian seasonal rainfall variability and pre-diction using canonical correlation analysis (CCA)rdquo EarthSciences vol 4 no 3 pp 112ndash119 2015

[14] A Mustefa ldquoReproduction and survival analysis of Boer andtheir crosses with Central Highland goats in EthiopiardquoLivestock Research for Rural Development vol 31 no 10 2019

[15] A Mustefa S Gizaw S Banerjee and A Abebe ldquoGrowthperformance of Boer goats and their F1 and F2 crosses andbackcrosses with central highland goats in Ethiopiardquo LivestockResearch for Rural Development vol 31 no 6 2019

[16] P D Allison Survival Analysis Using SAS A Practical GuideSAS Institute Cary NC USA 2010

[17] E L Kaplan and P Meier ldquoNonparametric estimation fromincomplete observationsrdquo Journal of the American StatisticalAssociation vol 53 no 282 pp 457ndash481 1958

[18] J Meyers ldquoe NEWSURV family of macros an update onthe survival plotting macroNEWSURV and an introductionto expansion macrosrdquo in Proceedings of the Pharma SUG2017 pp 14ndash17 Rochester MN USA 2017

[19] SAS Base SAS 94 Procedures Guide SAS Institute Inc CaryNC USA 94 edition 2015

[20] D Y Lin and L J Wei ldquoe robust inference for the coxproportional hazards modelrdquo Journal of the American Sta-tistical Association vol 84 no 408 pp 1074ndash1078 1989

[21] M H Al-Gaabary S A Osman and A F Oreiby ldquoCaseouslymphadenitis in sheep and goats clinical epidemiologicaland preventive studiesrdquo Small Ruminant Research vol 87no 1ndash3 pp 116ndash121 2009

[22] M W Paton S B Walker I R Rose and G F WattldquoPrevalence of caseous lymphadenitis and usage of caseouslymphadenitis vaccines in sheep flocksrdquo Australian Veteri-nary Journal vol 81 no 1-2 pp 91ndash95 2003

[23] D Abebe and T Sisay Tessema ldquoDetermination ofCor-ynebacterium pseudotuberculosisprevalence and antimicro-bial susceptibility pattern of isolates from lymph nodes ofsheep and goats at an organic export abattoir ModjoEthiopiardquo Letters in Applied Microbiology vol 61 no 5pp 469ndash476 2015

[24] P W Michael ldquoe epidemiology and control of caseouslymphadenitis in Australian sheep flocksrdquo in PhD School of

Veterinary and Biomedical Sciences Murdoch UniversityMurdoch Australia 2010

[25] R Ghanbarpour and M Khaleghiyan ldquoA study on caseouslymphadenitis in goatsrdquo Indian Veterinary Journal vol 82pp 1013-1014 2005

[26] E Alemnew E Yitagesu H Addis and A Areaya ldquoRetro-spective epidemiological study on goat disease in Debrebirhan agricultural Research center Ataye boer breedingevaluation and distribution site North Shoa EthiopiardquoBiomedicine and Nursing vol 6 no 1 pp 1ndash10 2020

[27] M H Al-Gaabary S A Osman M S Ahmed andA F Oreiby ldquoAbattoir survey on caseous lymphadenitis insheep and goats in Tanta Egyptrdquo Small Ruminant Researchvol 94 no 1ndash3 pp 117ndash124 2010

[28] B Ccediletinkaya M Karahan E Atil R Kalin T De Baere andM Vaneechoutte ldquoIdentification of Corynebacterium pseu-dotuberculosis isolates from sheep and goats by PCRrdquo Vet-erinary Microbiology vol 88 no 1 pp 75ndash83 2002

[29] W Morris F A Uzal and A Cipolla PyogranulomatousMeningoencephalitis in a Goat Due to CorynebacteriumUlcerans British Medical Journal Publishing Group LondonUK 2005

[30] T S P Tiwari A Golaz D T Yu et al ldquoInvestigations of 2cases of diphtheria-like illness due to toxigenic Corynebac-terium ulceransrdquo Clinical Infectious Diseases vol 46 no 3pp 395ndash401 2008

[31] D Weerasekera Characterization of Virulence Factors ofCorynebacterium Diphtheriae and Corynebacterium UlceransFriedrich-Alexander-Universitat Erlangen-Nurnberg (FAU)Erlangen Germany 2019

8 Veterinary Medicine International

twice or more relapse cases (Table 1) e incidence rate was014 cases per animal year

e most frequent cases occurred on the head regionlymph node of the parotid (92 (4299 relative percent)cases) prescapular (36 (1682)) and prefemoral (23(1075)) and the least frequent sites were the supra-mammary (234) cervical (187) and visceral organs(liver and lung) (187) (Table 2)

e typical clinical lesion is small and firm swelling ofexternal lymph nodes of different locations (Figure 2(a))e abscess is enclosed in a well-circumscribed fibrous tissueand when incised thick and often dry greyish or whitepurulent exudates Cut section of some of the affected lymphnodes revealed a characteristic onion-like appearance(Figure 2(b))

e unadjusted KaplanndashMeier survival function curvefrom birth or entry to farm to 60 months of the follow-upperiod of caseous lymphadenitis stratified based on the breedof goat season and age when the goat joined the farmindicates that the failure rate is steady and the mediansurvival time is around 565 months (46 years) (Figure 3(d))

ere was a significant difference between breed season andage (Figure 3) Newborn kid starts clinical cases by around 6

months of age and the failure rate is steady reaching theirmedian survival time at 368months (nearly 3 years old)(Figure 3(b)) At the end of the study the cumulative failurerates were 68 for newborn and 64 for yearlings ehazard is higher for newborn goats starting from first yearinterval up to the end while the hazard is relatively lower inthe first three years for yearling goats and higher after threeyears of age (Table 3) e survival rate is poor for Boer crosswith local Central Highland Goat and goats joined the farmduring the dry season (Figures 3(a) and 3(c))

Proportional hazard regression analysis of risk factorsusing the robust variance analysis of recurrent events andyear as a stratifying variable showed that age sex and breedwere associated with (p valuelt 005) caseous lymphadenitisoccurrence (survival) and season of the year when the goatjoined the farm was not associated with caseous lymphad-enitis survival Newborn goats compared with yearling agegoats have 4801 times higher probability of being infectedwith caseous lymphadenitis (p valuelt 00001) Female goats

(a) (b)

(c) (d)

Figure 2 Images of CLA prescapular LN case (a) incised retropharyngeal LN case (b) sample culture on blood agar (c) and Gram stain ofthe bacteria (d)

Table 1 Summary of caseous lymphadenitis cases with order of recurrence

Caseous lymphadenitis casesBreed N Positive () 1st case 2nd case 3rd case 4th case 5th case 6th caseBoer goat 314 53 (1688) 34 12 4 2 1 0BoertimesCHG 585 123 (2103) 72 28 11 7 4 1CHG 239 38 (159) 24 9 3 2 0 0Total 1138 214 (1880) 130 49 18 11 5 1Note CHG Central Highland Goat

4 Veterinary Medicine International

have 1856 times higher rate of being infected compared withmale goats (p value 00023) Pure Boer goat breeds have4217 times higher rate of being infected (p valuelt 00001)and Boer cross with Central Highland Goat breeds have4562 times higher rate of being infected (p value lt 00001)compared with local Central Highland Goat Breed goats(Table 4)

32 Bacteriological and Biolog MicroStation with GEN IIIMicroplate System Results From 32 pus samples of CLAsuspected goats we were able to recover pure colonies ofbacteria (Figure 2(c)) All of the samples were found to bepositive for C pseudotuberculosis based on cultural exam-ination All isolates of C pseudotuberculosis were Gram-positive pleomorphic rod (Figure 2(d)) catalase-positiveurease-positive antagonistic haemolysis with Staphylococcusaureus for phospholipase D (PLD) production and nitrate-negative [4] Out of 12 bacterial cultures tested using BiologMicroStation with GEN III microplate system results 10were C pseudotuberculosis and 2 of them were C ulcerans

4 Discussions

41 Descriptive Statistics and Survival Analysis e presentstudy shows the prevalence of CLA as 188 and the in-cidence rate as 014 cases per animal year e cumulativefailure rates were 68 for newborn aged goats and 64 foryearling aged goats is result indicates a high rate of CLAinfection rate at Ataye goat farm e cases were charac-terized by poor response to local and systemic antibiotictreatments e farm veterinarians cost a considerable timeto treat the frequent cases including the recurrent abscessfollowing incision local treatment by iodine and savlonand systemic antibiotic treatments using long-actingoxytetracycline

e current prevalence is in line with reports abroad1923 prevalence by Al-Gaabary et al [21] 26 preva-lence by Paton [22] and in Ethiopia 15 by Fikre andAbraha [10] e current port is relatively higher than mostreports in Ethiopia 47 by Molla [12] 117 by Abebe andSisay [23] and 10 by Hunduma et al [11] e variations

in the disease frequency between different studies may beattributed to the differences in the management systemsand climatic conditions in each study where the viability ofthe causative organism in the contaminated environment isgreatly affected by ambient temperature and it may also beattributed to the endemic nature of the disease which leadsto a variation in animal immunity and the degree of animalsusceptibility [21] In Australia the prevalence of CLA haddecreased from over 50 in the 1770s to approximately20 in the late 1990s through the use of recommendedCLA vaccine [22 24] e higher rate of infection in ourstudy was due to semi-intensive management of goats ahigher density of flocks on the smaller grazing land higherdensity at the barn and the lower quarantine practice ofclinical cases in the farm where all of them aggravates thetransmission rare of the disease ere is also no vaccineavailable in the country

e most affected superficial lymph node was theparotid lymph node Similar results were reported in[2 10] ese results may be attributed to the habit ofgoats that tend to scratch their shoulders and headsagainst walls and fences or any hard objects resulting in ahigh percentage of superficial parotid mandibular cer-vical and prefemoral lymph node infection because itdrains the shoulder region [10]

e hazard of CLA was higher (plt 0001) in the new-born than in the yearling age group is result contradictsfrom other findings [10 21] where age groups below 1 yearare at a lower riskis may be due to variation in the type ofstudy and age classification method In this result new casesare started at around 6 months of age e higher incidencerate in the newborn is due to the poor immunity of kids

Female goats were at higher (plt 00023) risk of infectionthan male goats Similar reports indicated a higher preva-lence of CLA in female groups [21 25] ese results may beattributed to the fact that does usually reared for older agesthan bucks as well as a relatively higher number of doesusually reared in one group resulting in a high rate ofcontact However a fewer number of males are kept togethermainly for the mating purpose of the farm [14 15]

Breed variation was the other important risk factor in theproportional hazard analysis Boer and Boer cross with local

Table 2 Summary of caseous lymphadenitis cases with lymph node location

Goat breedCLA location Boer goat BoertimesCHG CHG Total (relative )Parotid LN 21 55 16 92 (4299)Prescapular LN 10 21 5 36 (1682)Prefemoral LN 2 13 8 23 (1075)Undefined LN 2 12 0 14 (654)Mandibular LN 3 4 4 11 (514)Pharyngeal LN 4 7 0 11 (514)Multiple LNs 2 7 0 9 (421)Skin area 1 2 2 5 (234)Supramammary LN 2 1 2 5 (234)Cervical LN 3 1 0 4 (187)Visceral organs LN 3 0 1 4 (187)Overall cases N () 53314 (1688) 123585 (2103) 38239 (1590) 2141138 (1880)Note CHG Central Highland Goat CLA caseous lymphadenitis LN lymph node

Veterinary Medicine International 5

Central Highland Goats were at higher risk (plt 00001)compared with the local Central Highland Goat breedsGenerally the imported Boer goats are at higher risk tovarious disease conditions [26] is may be due to thehigher resistance of local breeds due to adaptation [12]

42 Bacteriological and Biolog MicroStation with GEN IIIMicroplate System Results We recovered 32C pseudotuberculosis bacteria from all 32 cultured abscesssamples From 12 pure culture samples tested using the Biolog-based test 10 of themwere C pseudotuberculosis and 2 of themwere C ulcerans positive However all of the 12 samples wereC pseudotuberculosis positive based on the biochemical testmethod e Biolog-based test screened the 2 samples as Culcerans e current result is in line with most previous

findings C pseudotuberculosis were the most frequent isolatedbacteria of clinical CLA abscess [10 21 23 25 27]e presentresult of 2 C ulcerans based on the Biolog test is the first reportin Ethiopia Although the differentiation between C ulceransand C pseudotuberculosis was based on a single biochemicalreaction the trehalose test the present results are in agreementwith previous studies [28] and indicate that the microorganismisolated in the present study was C ulcerans ere are alsoreports indicating that C ulcerans was isolated from clinicalcases of goat [29] C ulcerans is an emerging zoonotic diseasethat causes diphtheria like illness in humans [30 31]

5 Conclusion and Recommendations

Clinical and bacteriological study of the caseous lymphad-enitis indicates that the high prevalence of caseous

Breed Total Event Median (95 CI)Boer goat 314 53 650 (544-NE)Boer x CHG 585 123 368 (327-497)CHG 239 38 NE (565-NE)

10095

85

75

65

55

45

35

250 10 20 30

Goat age (months)

Surv

ival

(per

cent

age)

40 50 60

(a)

10095

85

75

65

55

45

35

250 10 20 30

Goat age (months)

Surv

ival

(per

cent

age)

40 50 60

Age Total Event Median (95 CI)764 145 368 (333-497)Newborn

Yearling 374 69 845 (600-NE)

(b)100

95

85

75

65

55

45

35

250 10 20 30

Goat age (months)

Surv

ival

(per

cent

age)

40 50 60

Total Event Median (95 CI)Season399 78 315 (260-NE)379 89 497 (460-692)

DryShort rainySummer 363 47 845 (668-NE)

(c)

10095

85

75

65

55

45

35

25

0 12 186 24 30 36Goat age (months)

Surv

ival

(per

cent

age)

42 48 54 60

Total Event

No at risk1138 613 519 293 108 48

Median (95 CI)1138 214 565 (508-692)

(d)

Figure 3 KaplanndashMeier survival function curve of caseous lymphadenitis cases from birth or entry to farm to 60 months of the follow-upperiod

6 Veterinary Medicine International

lymphadenitis in this goat farm Moreover repeated abscessoccurs after treatment Laboratory work reveals that Cpseudotuberculosis and C ulcerans were isolated bacteriathat cause abscess disease us the frequent abscess aftertreatment indicates poor response of the disease to differentantibiotics and antiseptic chemicals Control and preventionin sheep and goat farms should focus on quarantine andculling of positive animals and vaccination with the CLAvaccine

Data Availability

e datasets used to support the findings of this study areavailable from the corresponding author upon request

Conflicts of Interest

e authors declare that there are no conflicts of interestregarding the publication of this paper

Acknowledgments

is study was supported by Amhara Regional AgriculturalResearch Center (LsAhSh13DB-201518)

References

[1] S Ivanovic M Zutic I Pavlovic and M Zujovic ldquoCaseouslymphadenitis in goatsrdquo Biotechnology in Animal Husbandryvol 25 no 5-6-2 pp 999ndash1007 2009

[2] L H Williamson ldquoCaseous lymphadenitis in small rumi-nantsrdquo Veterinary Clinics of North America Food AnimalPractice vol 17 no 2 pp 359ndash371 2001

[3] G J Baird and M C Fontaine ldquoCorynebacterium pseudotu-berculosis and its role in ovine caseous lymphadenitisrdquo Journal ofComparative Pathology vol 137 no 4 pp 179ndash210 2007

[4] P Quin M Carter B Markey and E Carter ldquoCorynebac-terium species and Rhodococcus equirdquo in Clinical VeterinaryMicrobiology pp 137ndash143 Elsevier London UK 2004

[5] G J Baird and F E Malone ldquoControl of caseous lymph-adenitis in six sheep flocks using clinical examination andregular ELISA testingrdquo Veterinary Record vol 166 no 12pp 358ndash362 2010

[6] D P Dercksen J M A Brinkhof T Dekker-Nooren et al ldquoAcomparison of four serological tests for the diagnosis of ca-seous lymphadenitis in sheep and goatsrdquo Veterinary Micro-biology vol 75 no 2 pp 167ndash175 2000

[7] F A Dorella L Carvalho Pacheco S C Oliveira A Miyoshiand V Azevedo ldquoCorynebacterium pseudotuberculosismicrobiology biochemical properties pathogenesis andmolecular studies of virulencerdquo Veterinary Research vol 37no 2 pp 201ndash218 2006

Table 4 Proportional hazard regression analysis results of explanatory variables effect on caseous lymphadenitis with robust standarderrors

Variables Parameter estimate Standard error St err ratio HR 95 HR CI p valueAge Newborn vs yearling 156880 029319 0827 4801 [2702ndash8529] lt00001Sex Female vs male 061824 020285 1159 1856 [1247ndash2762] 00023

Breed Boer vs CHG 143907 022716 0657 4217 [2702ndash6582] lt00001BoertimesCHG vs CHG 151778 037440 0912 4562 [2190ndash9503] lt00001

Season Summer vs short rain 019403 029058 1208 1214 [0687ndash2146] 05043Dry vs short rain 004796 017486 0948 1049 [0745ndash1478] 07839

Note CI confidence interval St err standard error HR hazard ratio CHG Central Highland Goat

Table 3 Life table of CLA cases stratified based on the age of goats

Age groupInterval(months) Total Cases Lost Cumulative failures Hazard

95 CI hazardLower Upper

Newborn

0 12 764 61 439 011 0010 0007 001212 24 264 48 80 030 0020 0014 002624 36 136 21 53 044 0018 0010 002536 48 62 9 17 053 0015 0005 002548 60 36 5 22 062 0019 0002 003560 72 9 1 4 068 0013 0000 003872 84 4 0 4 068 0000

Yearling

0 12 374 16 103 005 0004 0002 000612 24 255 16 82 012 0007 0003 001024 36 157 4 33 015 0002 0000 000536 48 120 15 33 027 0013 0007 002048 60 72 11 22 040 0017 0007 002660 72 39 3 13 046 0008 0000 001772 84 23 1 6 048 0004 0000 001384 96 16 3 12 064 0029 0000 006296 108 1 0 1 064 0000

Veterinary Medicine International 7

[8] J Arsenault C Girard P Dubreuil et al ldquoPrevalence of andcarcass condemnation from maedi-visna paratuberculosisand caseous lymphadenitis in culled sheep from QuebecCanadardquo Preventive Veterinary Medicine vol 59 no 1-2pp 67ndash81 2003

[9] M W Paton A R Mercy F C Wilkinson J J GardnerS S Sutherland and T M Ellis ldquoe effects of caseouslymphadenitis on wool production and bodyweight in youngsheeprdquo Australian Veterinary Journal vol 65 no 4pp 117ndash119 1988

[10] Z Fikre and G K Abraha ldquoCaseous lymphadenitis in goatsfrom Borena Range land south Ethiopia slaughtered at Lunaexport abattoirrdquo Journal of Veterinary Medicine and AnimalHealth vol 6 no 6 pp 168ndash173 2014

[11] D Hunduma W Tigre M Wagari and F Regassa ldquoPre-liminary study on major health problems of the newly in-troduced Boer goat breed in EthiopiardquoWorld Applied SciencesJournal vol 11 no 7 pp 803ndash807 2010

[12] B Molla ldquoe health performance of imported Boer goat(Capra hircus) and their crosses with Woito-guji goat breedsin South Omo Zone South-Western Ethiopiardquo TropicalAnimal Health and Production vol 48 no 4 pp 855ndash8612016

[13] K Fekadu ldquoEthiopian seasonal rainfall variability and pre-diction using canonical correlation analysis (CCA)rdquo EarthSciences vol 4 no 3 pp 112ndash119 2015

[14] A Mustefa ldquoReproduction and survival analysis of Boer andtheir crosses with Central Highland goats in EthiopiardquoLivestock Research for Rural Development vol 31 no 10 2019

[15] A Mustefa S Gizaw S Banerjee and A Abebe ldquoGrowthperformance of Boer goats and their F1 and F2 crosses andbackcrosses with central highland goats in Ethiopiardquo LivestockResearch for Rural Development vol 31 no 6 2019

[16] P D Allison Survival Analysis Using SAS A Practical GuideSAS Institute Cary NC USA 2010

[17] E L Kaplan and P Meier ldquoNonparametric estimation fromincomplete observationsrdquo Journal of the American StatisticalAssociation vol 53 no 282 pp 457ndash481 1958

[18] J Meyers ldquoe NEWSURV family of macros an update onthe survival plotting macroNEWSURV and an introductionto expansion macrosrdquo in Proceedings of the Pharma SUG2017 pp 14ndash17 Rochester MN USA 2017

[19] SAS Base SAS 94 Procedures Guide SAS Institute Inc CaryNC USA 94 edition 2015

[20] D Y Lin and L J Wei ldquoe robust inference for the coxproportional hazards modelrdquo Journal of the American Sta-tistical Association vol 84 no 408 pp 1074ndash1078 1989

[21] M H Al-Gaabary S A Osman and A F Oreiby ldquoCaseouslymphadenitis in sheep and goats clinical epidemiologicaland preventive studiesrdquo Small Ruminant Research vol 87no 1ndash3 pp 116ndash121 2009

[22] M W Paton S B Walker I R Rose and G F WattldquoPrevalence of caseous lymphadenitis and usage of caseouslymphadenitis vaccines in sheep flocksrdquo Australian Veteri-nary Journal vol 81 no 1-2 pp 91ndash95 2003

[23] D Abebe and T Sisay Tessema ldquoDetermination ofCor-ynebacterium pseudotuberculosisprevalence and antimicro-bial susceptibility pattern of isolates from lymph nodes ofsheep and goats at an organic export abattoir ModjoEthiopiardquo Letters in Applied Microbiology vol 61 no 5pp 469ndash476 2015

[24] P W Michael ldquoe epidemiology and control of caseouslymphadenitis in Australian sheep flocksrdquo in PhD School of

Veterinary and Biomedical Sciences Murdoch UniversityMurdoch Australia 2010

[25] R Ghanbarpour and M Khaleghiyan ldquoA study on caseouslymphadenitis in goatsrdquo Indian Veterinary Journal vol 82pp 1013-1014 2005

[26] E Alemnew E Yitagesu H Addis and A Areaya ldquoRetro-spective epidemiological study on goat disease in Debrebirhan agricultural Research center Ataye boer breedingevaluation and distribution site North Shoa EthiopiardquoBiomedicine and Nursing vol 6 no 1 pp 1ndash10 2020

[27] M H Al-Gaabary S A Osman M S Ahmed andA F Oreiby ldquoAbattoir survey on caseous lymphadenitis insheep and goats in Tanta Egyptrdquo Small Ruminant Researchvol 94 no 1ndash3 pp 117ndash124 2010

[28] B Ccediletinkaya M Karahan E Atil R Kalin T De Baere andM Vaneechoutte ldquoIdentification of Corynebacterium pseu-dotuberculosis isolates from sheep and goats by PCRrdquo Vet-erinary Microbiology vol 88 no 1 pp 75ndash83 2002

[29] W Morris F A Uzal and A Cipolla PyogranulomatousMeningoencephalitis in a Goat Due to CorynebacteriumUlcerans British Medical Journal Publishing Group LondonUK 2005

[30] T S P Tiwari A Golaz D T Yu et al ldquoInvestigations of 2cases of diphtheria-like illness due to toxigenic Corynebac-terium ulceransrdquo Clinical Infectious Diseases vol 46 no 3pp 395ndash401 2008

[31] D Weerasekera Characterization of Virulence Factors ofCorynebacterium Diphtheriae and Corynebacterium UlceransFriedrich-Alexander-Universitat Erlangen-Nurnberg (FAU)Erlangen Germany 2019

8 Veterinary Medicine International

have 1856 times higher rate of being infected compared withmale goats (p value 00023) Pure Boer goat breeds have4217 times higher rate of being infected (p valuelt 00001)and Boer cross with Central Highland Goat breeds have4562 times higher rate of being infected (p value lt 00001)compared with local Central Highland Goat Breed goats(Table 4)

32 Bacteriological and Biolog MicroStation with GEN IIIMicroplate System Results From 32 pus samples of CLAsuspected goats we were able to recover pure colonies ofbacteria (Figure 2(c)) All of the samples were found to bepositive for C pseudotuberculosis based on cultural exam-ination All isolates of C pseudotuberculosis were Gram-positive pleomorphic rod (Figure 2(d)) catalase-positiveurease-positive antagonistic haemolysis with Staphylococcusaureus for phospholipase D (PLD) production and nitrate-negative [4] Out of 12 bacterial cultures tested using BiologMicroStation with GEN III microplate system results 10were C pseudotuberculosis and 2 of them were C ulcerans

4 Discussions

41 Descriptive Statistics and Survival Analysis e presentstudy shows the prevalence of CLA as 188 and the in-cidence rate as 014 cases per animal year e cumulativefailure rates were 68 for newborn aged goats and 64 foryearling aged goats is result indicates a high rate of CLAinfection rate at Ataye goat farm e cases were charac-terized by poor response to local and systemic antibiotictreatments e farm veterinarians cost a considerable timeto treat the frequent cases including the recurrent abscessfollowing incision local treatment by iodine and savlonand systemic antibiotic treatments using long-actingoxytetracycline

e current prevalence is in line with reports abroad1923 prevalence by Al-Gaabary et al [21] 26 preva-lence by Paton [22] and in Ethiopia 15 by Fikre andAbraha [10] e current port is relatively higher than mostreports in Ethiopia 47 by Molla [12] 117 by Abebe andSisay [23] and 10 by Hunduma et al [11] e variations

in the disease frequency between different studies may beattributed to the differences in the management systemsand climatic conditions in each study where the viability ofthe causative organism in the contaminated environment isgreatly affected by ambient temperature and it may also beattributed to the endemic nature of the disease which leadsto a variation in animal immunity and the degree of animalsusceptibility [21] In Australia the prevalence of CLA haddecreased from over 50 in the 1770s to approximately20 in the late 1990s through the use of recommendedCLA vaccine [22 24] e higher rate of infection in ourstudy was due to semi-intensive management of goats ahigher density of flocks on the smaller grazing land higherdensity at the barn and the lower quarantine practice ofclinical cases in the farm where all of them aggravates thetransmission rare of the disease ere is also no vaccineavailable in the country

e most affected superficial lymph node was theparotid lymph node Similar results were reported in[2 10] ese results may be attributed to the habit ofgoats that tend to scratch their shoulders and headsagainst walls and fences or any hard objects resulting in ahigh percentage of superficial parotid mandibular cer-vical and prefemoral lymph node infection because itdrains the shoulder region [10]

e hazard of CLA was higher (plt 0001) in the new-born than in the yearling age group is result contradictsfrom other findings [10 21] where age groups below 1 yearare at a lower riskis may be due to variation in the type ofstudy and age classification method In this result new casesare started at around 6 months of age e higher incidencerate in the newborn is due to the poor immunity of kids

Female goats were at higher (plt 00023) risk of infectionthan male goats Similar reports indicated a higher preva-lence of CLA in female groups [21 25] ese results may beattributed to the fact that does usually reared for older agesthan bucks as well as a relatively higher number of doesusually reared in one group resulting in a high rate ofcontact However a fewer number of males are kept togethermainly for the mating purpose of the farm [14 15]

Breed variation was the other important risk factor in theproportional hazard analysis Boer and Boer cross with local

Table 2 Summary of caseous lymphadenitis cases with lymph node location

Goat breedCLA location Boer goat BoertimesCHG CHG Total (relative )Parotid LN 21 55 16 92 (4299)Prescapular LN 10 21 5 36 (1682)Prefemoral LN 2 13 8 23 (1075)Undefined LN 2 12 0 14 (654)Mandibular LN 3 4 4 11 (514)Pharyngeal LN 4 7 0 11 (514)Multiple LNs 2 7 0 9 (421)Skin area 1 2 2 5 (234)Supramammary LN 2 1 2 5 (234)Cervical LN 3 1 0 4 (187)Visceral organs LN 3 0 1 4 (187)Overall cases N () 53314 (1688) 123585 (2103) 38239 (1590) 2141138 (1880)Note CHG Central Highland Goat CLA caseous lymphadenitis LN lymph node

Veterinary Medicine International 5

Central Highland Goats were at higher risk (plt 00001)compared with the local Central Highland Goat breedsGenerally the imported Boer goats are at higher risk tovarious disease conditions [26] is may be due to thehigher resistance of local breeds due to adaptation [12]

42 Bacteriological and Biolog MicroStation with GEN IIIMicroplate System Results We recovered 32C pseudotuberculosis bacteria from all 32 cultured abscesssamples From 12 pure culture samples tested using the Biolog-based test 10 of themwere C pseudotuberculosis and 2 of themwere C ulcerans positive However all of the 12 samples wereC pseudotuberculosis positive based on the biochemical testmethod e Biolog-based test screened the 2 samples as Culcerans e current result is in line with most previous

findings C pseudotuberculosis were the most frequent isolatedbacteria of clinical CLA abscess [10 21 23 25 27]e presentresult of 2 C ulcerans based on the Biolog test is the first reportin Ethiopia Although the differentiation between C ulceransand C pseudotuberculosis was based on a single biochemicalreaction the trehalose test the present results are in agreementwith previous studies [28] and indicate that the microorganismisolated in the present study was C ulcerans ere are alsoreports indicating that C ulcerans was isolated from clinicalcases of goat [29] C ulcerans is an emerging zoonotic diseasethat causes diphtheria like illness in humans [30 31]

5 Conclusion and Recommendations

Clinical and bacteriological study of the caseous lymphad-enitis indicates that the high prevalence of caseous

Breed Total Event Median (95 CI)Boer goat 314 53 650 (544-NE)Boer x CHG 585 123 368 (327-497)CHG 239 38 NE (565-NE)

10095

85

75

65

55

45

35

250 10 20 30

Goat age (months)

Surv

ival

(per

cent

age)

40 50 60

(a)

10095

85

75

65

55

45

35

250 10 20 30

Goat age (months)

Surv

ival

(per

cent

age)

40 50 60

Age Total Event Median (95 CI)764 145 368 (333-497)Newborn

Yearling 374 69 845 (600-NE)

(b)100

95

85

75

65

55

45

35

250 10 20 30

Goat age (months)

Surv

ival

(per

cent

age)

40 50 60

Total Event Median (95 CI)Season399 78 315 (260-NE)379 89 497 (460-692)

DryShort rainySummer 363 47 845 (668-NE)

(c)

10095

85

75

65

55

45

35

25

0 12 186 24 30 36Goat age (months)

Surv

ival

(per

cent

age)

42 48 54 60

Total Event

No at risk1138 613 519 293 108 48

Median (95 CI)1138 214 565 (508-692)

(d)

Figure 3 KaplanndashMeier survival function curve of caseous lymphadenitis cases from birth or entry to farm to 60 months of the follow-upperiod

6 Veterinary Medicine International

lymphadenitis in this goat farm Moreover repeated abscessoccurs after treatment Laboratory work reveals that Cpseudotuberculosis and C ulcerans were isolated bacteriathat cause abscess disease us the frequent abscess aftertreatment indicates poor response of the disease to differentantibiotics and antiseptic chemicals Control and preventionin sheep and goat farms should focus on quarantine andculling of positive animals and vaccination with the CLAvaccine

Data Availability

e datasets used to support the findings of this study areavailable from the corresponding author upon request

Conflicts of Interest

e authors declare that there are no conflicts of interestregarding the publication of this paper

Acknowledgments

is study was supported by Amhara Regional AgriculturalResearch Center (LsAhSh13DB-201518)

References

[1] S Ivanovic M Zutic I Pavlovic and M Zujovic ldquoCaseouslymphadenitis in goatsrdquo Biotechnology in Animal Husbandryvol 25 no 5-6-2 pp 999ndash1007 2009

[2] L H Williamson ldquoCaseous lymphadenitis in small rumi-nantsrdquo Veterinary Clinics of North America Food AnimalPractice vol 17 no 2 pp 359ndash371 2001

[3] G J Baird and M C Fontaine ldquoCorynebacterium pseudotu-berculosis and its role in ovine caseous lymphadenitisrdquo Journal ofComparative Pathology vol 137 no 4 pp 179ndash210 2007

[4] P Quin M Carter B Markey and E Carter ldquoCorynebac-terium species and Rhodococcus equirdquo in Clinical VeterinaryMicrobiology pp 137ndash143 Elsevier London UK 2004

[5] G J Baird and F E Malone ldquoControl of caseous lymph-adenitis in six sheep flocks using clinical examination andregular ELISA testingrdquo Veterinary Record vol 166 no 12pp 358ndash362 2010

[6] D P Dercksen J M A Brinkhof T Dekker-Nooren et al ldquoAcomparison of four serological tests for the diagnosis of ca-seous lymphadenitis in sheep and goatsrdquo Veterinary Micro-biology vol 75 no 2 pp 167ndash175 2000

[7] F A Dorella L Carvalho Pacheco S C Oliveira A Miyoshiand V Azevedo ldquoCorynebacterium pseudotuberculosismicrobiology biochemical properties pathogenesis andmolecular studies of virulencerdquo Veterinary Research vol 37no 2 pp 201ndash218 2006

Table 4 Proportional hazard regression analysis results of explanatory variables effect on caseous lymphadenitis with robust standarderrors

Variables Parameter estimate Standard error St err ratio HR 95 HR CI p valueAge Newborn vs yearling 156880 029319 0827 4801 [2702ndash8529] lt00001Sex Female vs male 061824 020285 1159 1856 [1247ndash2762] 00023

Breed Boer vs CHG 143907 022716 0657 4217 [2702ndash6582] lt00001BoertimesCHG vs CHG 151778 037440 0912 4562 [2190ndash9503] lt00001

Season Summer vs short rain 019403 029058 1208 1214 [0687ndash2146] 05043Dry vs short rain 004796 017486 0948 1049 [0745ndash1478] 07839

Note CI confidence interval St err standard error HR hazard ratio CHG Central Highland Goat

Table 3 Life table of CLA cases stratified based on the age of goats

Age groupInterval(months) Total Cases Lost Cumulative failures Hazard

95 CI hazardLower Upper

Newborn

0 12 764 61 439 011 0010 0007 001212 24 264 48 80 030 0020 0014 002624 36 136 21 53 044 0018 0010 002536 48 62 9 17 053 0015 0005 002548 60 36 5 22 062 0019 0002 003560 72 9 1 4 068 0013 0000 003872 84 4 0 4 068 0000

Yearling

0 12 374 16 103 005 0004 0002 000612 24 255 16 82 012 0007 0003 001024 36 157 4 33 015 0002 0000 000536 48 120 15 33 027 0013 0007 002048 60 72 11 22 040 0017 0007 002660 72 39 3 13 046 0008 0000 001772 84 23 1 6 048 0004 0000 001384 96 16 3 12 064 0029 0000 006296 108 1 0 1 064 0000

Veterinary Medicine International 7

[8] J Arsenault C Girard P Dubreuil et al ldquoPrevalence of andcarcass condemnation from maedi-visna paratuberculosisand caseous lymphadenitis in culled sheep from QuebecCanadardquo Preventive Veterinary Medicine vol 59 no 1-2pp 67ndash81 2003

[9] M W Paton A R Mercy F C Wilkinson J J GardnerS S Sutherland and T M Ellis ldquoe effects of caseouslymphadenitis on wool production and bodyweight in youngsheeprdquo Australian Veterinary Journal vol 65 no 4pp 117ndash119 1988

[10] Z Fikre and G K Abraha ldquoCaseous lymphadenitis in goatsfrom Borena Range land south Ethiopia slaughtered at Lunaexport abattoirrdquo Journal of Veterinary Medicine and AnimalHealth vol 6 no 6 pp 168ndash173 2014

[11] D Hunduma W Tigre M Wagari and F Regassa ldquoPre-liminary study on major health problems of the newly in-troduced Boer goat breed in EthiopiardquoWorld Applied SciencesJournal vol 11 no 7 pp 803ndash807 2010

[12] B Molla ldquoe health performance of imported Boer goat(Capra hircus) and their crosses with Woito-guji goat breedsin South Omo Zone South-Western Ethiopiardquo TropicalAnimal Health and Production vol 48 no 4 pp 855ndash8612016

[13] K Fekadu ldquoEthiopian seasonal rainfall variability and pre-diction using canonical correlation analysis (CCA)rdquo EarthSciences vol 4 no 3 pp 112ndash119 2015

[14] A Mustefa ldquoReproduction and survival analysis of Boer andtheir crosses with Central Highland goats in EthiopiardquoLivestock Research for Rural Development vol 31 no 10 2019

[15] A Mustefa S Gizaw S Banerjee and A Abebe ldquoGrowthperformance of Boer goats and their F1 and F2 crosses andbackcrosses with central highland goats in Ethiopiardquo LivestockResearch for Rural Development vol 31 no 6 2019

[16] P D Allison Survival Analysis Using SAS A Practical GuideSAS Institute Cary NC USA 2010

[17] E L Kaplan and P Meier ldquoNonparametric estimation fromincomplete observationsrdquo Journal of the American StatisticalAssociation vol 53 no 282 pp 457ndash481 1958

[18] J Meyers ldquoe NEWSURV family of macros an update onthe survival plotting macroNEWSURV and an introductionto expansion macrosrdquo in Proceedings of the Pharma SUG2017 pp 14ndash17 Rochester MN USA 2017

[19] SAS Base SAS 94 Procedures Guide SAS Institute Inc CaryNC USA 94 edition 2015

[20] D Y Lin and L J Wei ldquoe robust inference for the coxproportional hazards modelrdquo Journal of the American Sta-tistical Association vol 84 no 408 pp 1074ndash1078 1989

[21] M H Al-Gaabary S A Osman and A F Oreiby ldquoCaseouslymphadenitis in sheep and goats clinical epidemiologicaland preventive studiesrdquo Small Ruminant Research vol 87no 1ndash3 pp 116ndash121 2009

[22] M W Paton S B Walker I R Rose and G F WattldquoPrevalence of caseous lymphadenitis and usage of caseouslymphadenitis vaccines in sheep flocksrdquo Australian Veteri-nary Journal vol 81 no 1-2 pp 91ndash95 2003

[23] D Abebe and T Sisay Tessema ldquoDetermination ofCor-ynebacterium pseudotuberculosisprevalence and antimicro-bial susceptibility pattern of isolates from lymph nodes ofsheep and goats at an organic export abattoir ModjoEthiopiardquo Letters in Applied Microbiology vol 61 no 5pp 469ndash476 2015

[24] P W Michael ldquoe epidemiology and control of caseouslymphadenitis in Australian sheep flocksrdquo in PhD School of

Veterinary and Biomedical Sciences Murdoch UniversityMurdoch Australia 2010

[25] R Ghanbarpour and M Khaleghiyan ldquoA study on caseouslymphadenitis in goatsrdquo Indian Veterinary Journal vol 82pp 1013-1014 2005

[26] E Alemnew E Yitagesu H Addis and A Areaya ldquoRetro-spective epidemiological study on goat disease in Debrebirhan agricultural Research center Ataye boer breedingevaluation and distribution site North Shoa EthiopiardquoBiomedicine and Nursing vol 6 no 1 pp 1ndash10 2020

[27] M H Al-Gaabary S A Osman M S Ahmed andA F Oreiby ldquoAbattoir survey on caseous lymphadenitis insheep and goats in Tanta Egyptrdquo Small Ruminant Researchvol 94 no 1ndash3 pp 117ndash124 2010

[28] B Ccediletinkaya M Karahan E Atil R Kalin T De Baere andM Vaneechoutte ldquoIdentification of Corynebacterium pseu-dotuberculosis isolates from sheep and goats by PCRrdquo Vet-erinary Microbiology vol 88 no 1 pp 75ndash83 2002

[29] W Morris F A Uzal and A Cipolla PyogranulomatousMeningoencephalitis in a Goat Due to CorynebacteriumUlcerans British Medical Journal Publishing Group LondonUK 2005

[30] T S P Tiwari A Golaz D T Yu et al ldquoInvestigations of 2cases of diphtheria-like illness due to toxigenic Corynebac-terium ulceransrdquo Clinical Infectious Diseases vol 46 no 3pp 395ndash401 2008

[31] D Weerasekera Characterization of Virulence Factors ofCorynebacterium Diphtheriae and Corynebacterium UlceransFriedrich-Alexander-Universitat Erlangen-Nurnberg (FAU)Erlangen Germany 2019

8 Veterinary Medicine International

Central Highland Goats were at higher risk (plt 00001)compared with the local Central Highland Goat breedsGenerally the imported Boer goats are at higher risk tovarious disease conditions [26] is may be due to thehigher resistance of local breeds due to adaptation [12]

42 Bacteriological and Biolog MicroStation with GEN IIIMicroplate System Results We recovered 32C pseudotuberculosis bacteria from all 32 cultured abscesssamples From 12 pure culture samples tested using the Biolog-based test 10 of themwere C pseudotuberculosis and 2 of themwere C ulcerans positive However all of the 12 samples wereC pseudotuberculosis positive based on the biochemical testmethod e Biolog-based test screened the 2 samples as Culcerans e current result is in line with most previous

findings C pseudotuberculosis were the most frequent isolatedbacteria of clinical CLA abscess [10 21 23 25 27]e presentresult of 2 C ulcerans based on the Biolog test is the first reportin Ethiopia Although the differentiation between C ulceransand C pseudotuberculosis was based on a single biochemicalreaction the trehalose test the present results are in agreementwith previous studies [28] and indicate that the microorganismisolated in the present study was C ulcerans ere are alsoreports indicating that C ulcerans was isolated from clinicalcases of goat [29] C ulcerans is an emerging zoonotic diseasethat causes diphtheria like illness in humans [30 31]

5 Conclusion and Recommendations

Clinical and bacteriological study of the caseous lymphad-enitis indicates that the high prevalence of caseous

Breed Total Event Median (95 CI)Boer goat 314 53 650 (544-NE)Boer x CHG 585 123 368 (327-497)CHG 239 38 NE (565-NE)

10095

85

75

65

55

45

35

250 10 20 30

Goat age (months)

Surv

ival

(per

cent

age)

40 50 60

(a)

10095

85

75

65

55

45

35

250 10 20 30

Goat age (months)

Surv

ival

(per

cent

age)

40 50 60

Age Total Event Median (95 CI)764 145 368 (333-497)Newborn

Yearling 374 69 845 (600-NE)

(b)100

95

85

75

65

55

45

35

250 10 20 30

Goat age (months)

Surv

ival

(per

cent

age)

40 50 60

Total Event Median (95 CI)Season399 78 315 (260-NE)379 89 497 (460-692)

DryShort rainySummer 363 47 845 (668-NE)

(c)

10095

85

75

65

55

45

35

25

0 12 186 24 30 36Goat age (months)

Surv

ival

(per

cent

age)

42 48 54 60

Total Event

No at risk1138 613 519 293 108 48

Median (95 CI)1138 214 565 (508-692)

(d)

Figure 3 KaplanndashMeier survival function curve of caseous lymphadenitis cases from birth or entry to farm to 60 months of the follow-upperiod

6 Veterinary Medicine International

lymphadenitis in this goat farm Moreover repeated abscessoccurs after treatment Laboratory work reveals that Cpseudotuberculosis and C ulcerans were isolated bacteriathat cause abscess disease us the frequent abscess aftertreatment indicates poor response of the disease to differentantibiotics and antiseptic chemicals Control and preventionin sheep and goat farms should focus on quarantine andculling of positive animals and vaccination with the CLAvaccine

Data Availability

e datasets used to support the findings of this study areavailable from the corresponding author upon request

Conflicts of Interest

e authors declare that there are no conflicts of interestregarding the publication of this paper

Acknowledgments

is study was supported by Amhara Regional AgriculturalResearch Center (LsAhSh13DB-201518)

References

[1] S Ivanovic M Zutic I Pavlovic and M Zujovic ldquoCaseouslymphadenitis in goatsrdquo Biotechnology in Animal Husbandryvol 25 no 5-6-2 pp 999ndash1007 2009

[2] L H Williamson ldquoCaseous lymphadenitis in small rumi-nantsrdquo Veterinary Clinics of North America Food AnimalPractice vol 17 no 2 pp 359ndash371 2001

[3] G J Baird and M C Fontaine ldquoCorynebacterium pseudotu-berculosis and its role in ovine caseous lymphadenitisrdquo Journal ofComparative Pathology vol 137 no 4 pp 179ndash210 2007

[4] P Quin M Carter B Markey and E Carter ldquoCorynebac-terium species and Rhodococcus equirdquo in Clinical VeterinaryMicrobiology pp 137ndash143 Elsevier London UK 2004

[5] G J Baird and F E Malone ldquoControl of caseous lymph-adenitis in six sheep flocks using clinical examination andregular ELISA testingrdquo Veterinary Record vol 166 no 12pp 358ndash362 2010

[6] D P Dercksen J M A Brinkhof T Dekker-Nooren et al ldquoAcomparison of four serological tests for the diagnosis of ca-seous lymphadenitis in sheep and goatsrdquo Veterinary Micro-biology vol 75 no 2 pp 167ndash175 2000

[7] F A Dorella L Carvalho Pacheco S C Oliveira A Miyoshiand V Azevedo ldquoCorynebacterium pseudotuberculosismicrobiology biochemical properties pathogenesis andmolecular studies of virulencerdquo Veterinary Research vol 37no 2 pp 201ndash218 2006

Table 4 Proportional hazard regression analysis results of explanatory variables effect on caseous lymphadenitis with robust standarderrors

Variables Parameter estimate Standard error St err ratio HR 95 HR CI p valueAge Newborn vs yearling 156880 029319 0827 4801 [2702ndash8529] lt00001Sex Female vs male 061824 020285 1159 1856 [1247ndash2762] 00023

Breed Boer vs CHG 143907 022716 0657 4217 [2702ndash6582] lt00001BoertimesCHG vs CHG 151778 037440 0912 4562 [2190ndash9503] lt00001

Season Summer vs short rain 019403 029058 1208 1214 [0687ndash2146] 05043Dry vs short rain 004796 017486 0948 1049 [0745ndash1478] 07839

Note CI confidence interval St err standard error HR hazard ratio CHG Central Highland Goat

Table 3 Life table of CLA cases stratified based on the age of goats

Age groupInterval(months) Total Cases Lost Cumulative failures Hazard

95 CI hazardLower Upper

Newborn

0 12 764 61 439 011 0010 0007 001212 24 264 48 80 030 0020 0014 002624 36 136 21 53 044 0018 0010 002536 48 62 9 17 053 0015 0005 002548 60 36 5 22 062 0019 0002 003560 72 9 1 4 068 0013 0000 003872 84 4 0 4 068 0000

Yearling

0 12 374 16 103 005 0004 0002 000612 24 255 16 82 012 0007 0003 001024 36 157 4 33 015 0002 0000 000536 48 120 15 33 027 0013 0007 002048 60 72 11 22 040 0017 0007 002660 72 39 3 13 046 0008 0000 001772 84 23 1 6 048 0004 0000 001384 96 16 3 12 064 0029 0000 006296 108 1 0 1 064 0000

Veterinary Medicine International 7

[8] J Arsenault C Girard P Dubreuil et al ldquoPrevalence of andcarcass condemnation from maedi-visna paratuberculosisand caseous lymphadenitis in culled sheep from QuebecCanadardquo Preventive Veterinary Medicine vol 59 no 1-2pp 67ndash81 2003

[9] M W Paton A R Mercy F C Wilkinson J J GardnerS S Sutherland and T M Ellis ldquoe effects of caseouslymphadenitis on wool production and bodyweight in youngsheeprdquo Australian Veterinary Journal vol 65 no 4pp 117ndash119 1988

[10] Z Fikre and G K Abraha ldquoCaseous lymphadenitis in goatsfrom Borena Range land south Ethiopia slaughtered at Lunaexport abattoirrdquo Journal of Veterinary Medicine and AnimalHealth vol 6 no 6 pp 168ndash173 2014

[11] D Hunduma W Tigre M Wagari and F Regassa ldquoPre-liminary study on major health problems of the newly in-troduced Boer goat breed in EthiopiardquoWorld Applied SciencesJournal vol 11 no 7 pp 803ndash807 2010

[12] B Molla ldquoe health performance of imported Boer goat(Capra hircus) and their crosses with Woito-guji goat breedsin South Omo Zone South-Western Ethiopiardquo TropicalAnimal Health and Production vol 48 no 4 pp 855ndash8612016

[13] K Fekadu ldquoEthiopian seasonal rainfall variability and pre-diction using canonical correlation analysis (CCA)rdquo EarthSciences vol 4 no 3 pp 112ndash119 2015

[14] A Mustefa ldquoReproduction and survival analysis of Boer andtheir crosses with Central Highland goats in EthiopiardquoLivestock Research for Rural Development vol 31 no 10 2019

[15] A Mustefa S Gizaw S Banerjee and A Abebe ldquoGrowthperformance of Boer goats and their F1 and F2 crosses andbackcrosses with central highland goats in Ethiopiardquo LivestockResearch for Rural Development vol 31 no 6 2019

[16] P D Allison Survival Analysis Using SAS A Practical GuideSAS Institute Cary NC USA 2010

[17] E L Kaplan and P Meier ldquoNonparametric estimation fromincomplete observationsrdquo Journal of the American StatisticalAssociation vol 53 no 282 pp 457ndash481 1958

[18] J Meyers ldquoe NEWSURV family of macros an update onthe survival plotting macroNEWSURV and an introductionto expansion macrosrdquo in Proceedings of the Pharma SUG2017 pp 14ndash17 Rochester MN USA 2017

[19] SAS Base SAS 94 Procedures Guide SAS Institute Inc CaryNC USA 94 edition 2015

[20] D Y Lin and L J Wei ldquoe robust inference for the coxproportional hazards modelrdquo Journal of the American Sta-tistical Association vol 84 no 408 pp 1074ndash1078 1989

[21] M H Al-Gaabary S A Osman and A F Oreiby ldquoCaseouslymphadenitis in sheep and goats clinical epidemiologicaland preventive studiesrdquo Small Ruminant Research vol 87no 1ndash3 pp 116ndash121 2009

[22] M W Paton S B Walker I R Rose and G F WattldquoPrevalence of caseous lymphadenitis and usage of caseouslymphadenitis vaccines in sheep flocksrdquo Australian Veteri-nary Journal vol 81 no 1-2 pp 91ndash95 2003

[23] D Abebe and T Sisay Tessema ldquoDetermination ofCor-ynebacterium pseudotuberculosisprevalence and antimicro-bial susceptibility pattern of isolates from lymph nodes ofsheep and goats at an organic export abattoir ModjoEthiopiardquo Letters in Applied Microbiology vol 61 no 5pp 469ndash476 2015

[24] P W Michael ldquoe epidemiology and control of caseouslymphadenitis in Australian sheep flocksrdquo in PhD School of

Veterinary and Biomedical Sciences Murdoch UniversityMurdoch Australia 2010

[25] R Ghanbarpour and M Khaleghiyan ldquoA study on caseouslymphadenitis in goatsrdquo Indian Veterinary Journal vol 82pp 1013-1014 2005

[26] E Alemnew E Yitagesu H Addis and A Areaya ldquoRetro-spective epidemiological study on goat disease in Debrebirhan agricultural Research center Ataye boer breedingevaluation and distribution site North Shoa EthiopiardquoBiomedicine and Nursing vol 6 no 1 pp 1ndash10 2020

[27] M H Al-Gaabary S A Osman M S Ahmed andA F Oreiby ldquoAbattoir survey on caseous lymphadenitis insheep and goats in Tanta Egyptrdquo Small Ruminant Researchvol 94 no 1ndash3 pp 117ndash124 2010

[28] B Ccediletinkaya M Karahan E Atil R Kalin T De Baere andM Vaneechoutte ldquoIdentification of Corynebacterium pseu-dotuberculosis isolates from sheep and goats by PCRrdquo Vet-erinary Microbiology vol 88 no 1 pp 75ndash83 2002

[29] W Morris F A Uzal and A Cipolla PyogranulomatousMeningoencephalitis in a Goat Due to CorynebacteriumUlcerans British Medical Journal Publishing Group LondonUK 2005

[30] T S P Tiwari A Golaz D T Yu et al ldquoInvestigations of 2cases of diphtheria-like illness due to toxigenic Corynebac-terium ulceransrdquo Clinical Infectious Diseases vol 46 no 3pp 395ndash401 2008

[31] D Weerasekera Characterization of Virulence Factors ofCorynebacterium Diphtheriae and Corynebacterium UlceransFriedrich-Alexander-Universitat Erlangen-Nurnberg (FAU)Erlangen Germany 2019

8 Veterinary Medicine International

lymphadenitis in this goat farm Moreover repeated abscessoccurs after treatment Laboratory work reveals that Cpseudotuberculosis and C ulcerans were isolated bacteriathat cause abscess disease us the frequent abscess aftertreatment indicates poor response of the disease to differentantibiotics and antiseptic chemicals Control and preventionin sheep and goat farms should focus on quarantine andculling of positive animals and vaccination with the CLAvaccine

Data Availability

e datasets used to support the findings of this study areavailable from the corresponding author upon request

Conflicts of Interest

e authors declare that there are no conflicts of interestregarding the publication of this paper

Acknowledgments

is study was supported by Amhara Regional AgriculturalResearch Center (LsAhSh13DB-201518)

References

[1] S Ivanovic M Zutic I Pavlovic and M Zujovic ldquoCaseouslymphadenitis in goatsrdquo Biotechnology in Animal Husbandryvol 25 no 5-6-2 pp 999ndash1007 2009

[2] L H Williamson ldquoCaseous lymphadenitis in small rumi-nantsrdquo Veterinary Clinics of North America Food AnimalPractice vol 17 no 2 pp 359ndash371 2001

[3] G J Baird and M C Fontaine ldquoCorynebacterium pseudotu-berculosis and its role in ovine caseous lymphadenitisrdquo Journal ofComparative Pathology vol 137 no 4 pp 179ndash210 2007

[4] P Quin M Carter B Markey and E Carter ldquoCorynebac-terium species and Rhodococcus equirdquo in Clinical VeterinaryMicrobiology pp 137ndash143 Elsevier London UK 2004

[5] G J Baird and F E Malone ldquoControl of caseous lymph-adenitis in six sheep flocks using clinical examination andregular ELISA testingrdquo Veterinary Record vol 166 no 12pp 358ndash362 2010

[6] D P Dercksen J M A Brinkhof T Dekker-Nooren et al ldquoAcomparison of four serological tests for the diagnosis of ca-seous lymphadenitis in sheep and goatsrdquo Veterinary Micro-biology vol 75 no 2 pp 167ndash175 2000

[7] F A Dorella L Carvalho Pacheco S C Oliveira A Miyoshiand V Azevedo ldquoCorynebacterium pseudotuberculosismicrobiology biochemical properties pathogenesis andmolecular studies of virulencerdquo Veterinary Research vol 37no 2 pp 201ndash218 2006

Table 4 Proportional hazard regression analysis results of explanatory variables effect on caseous lymphadenitis with robust standarderrors

Variables Parameter estimate Standard error St err ratio HR 95 HR CI p valueAge Newborn vs yearling 156880 029319 0827 4801 [2702ndash8529] lt00001Sex Female vs male 061824 020285 1159 1856 [1247ndash2762] 00023

Breed Boer vs CHG 143907 022716 0657 4217 [2702ndash6582] lt00001BoertimesCHG vs CHG 151778 037440 0912 4562 [2190ndash9503] lt00001

Season Summer vs short rain 019403 029058 1208 1214 [0687ndash2146] 05043Dry vs short rain 004796 017486 0948 1049 [0745ndash1478] 07839

Note CI confidence interval St err standard error HR hazard ratio CHG Central Highland Goat

Table 3 Life table of CLA cases stratified based on the age of goats

Age groupInterval(months) Total Cases Lost Cumulative failures Hazard

95 CI hazardLower Upper

Newborn

0 12 764 61 439 011 0010 0007 001212 24 264 48 80 030 0020 0014 002624 36 136 21 53 044 0018 0010 002536 48 62 9 17 053 0015 0005 002548 60 36 5 22 062 0019 0002 003560 72 9 1 4 068 0013 0000 003872 84 4 0 4 068 0000

Yearling

0 12 374 16 103 005 0004 0002 000612 24 255 16 82 012 0007 0003 001024 36 157 4 33 015 0002 0000 000536 48 120 15 33 027 0013 0007 002048 60 72 11 22 040 0017 0007 002660 72 39 3 13 046 0008 0000 001772 84 23 1 6 048 0004 0000 001384 96 16 3 12 064 0029 0000 006296 108 1 0 1 064 0000

Veterinary Medicine International 7

[8] J Arsenault C Girard P Dubreuil et al ldquoPrevalence of andcarcass condemnation from maedi-visna paratuberculosisand caseous lymphadenitis in culled sheep from QuebecCanadardquo Preventive Veterinary Medicine vol 59 no 1-2pp 67ndash81 2003

[9] M W Paton A R Mercy F C Wilkinson J J GardnerS S Sutherland and T M Ellis ldquoe effects of caseouslymphadenitis on wool production and bodyweight in youngsheeprdquo Australian Veterinary Journal vol 65 no 4pp 117ndash119 1988

[10] Z Fikre and G K Abraha ldquoCaseous lymphadenitis in goatsfrom Borena Range land south Ethiopia slaughtered at Lunaexport abattoirrdquo Journal of Veterinary Medicine and AnimalHealth vol 6 no 6 pp 168ndash173 2014

[11] D Hunduma W Tigre M Wagari and F Regassa ldquoPre-liminary study on major health problems of the newly in-troduced Boer goat breed in EthiopiardquoWorld Applied SciencesJournal vol 11 no 7 pp 803ndash807 2010

[12] B Molla ldquoe health performance of imported Boer goat(Capra hircus) and their crosses with Woito-guji goat breedsin South Omo Zone South-Western Ethiopiardquo TropicalAnimal Health and Production vol 48 no 4 pp 855ndash8612016

[13] K Fekadu ldquoEthiopian seasonal rainfall variability and pre-diction using canonical correlation analysis (CCA)rdquo EarthSciences vol 4 no 3 pp 112ndash119 2015

[14] A Mustefa ldquoReproduction and survival analysis of Boer andtheir crosses with Central Highland goats in EthiopiardquoLivestock Research for Rural Development vol 31 no 10 2019

[15] A Mustefa S Gizaw S Banerjee and A Abebe ldquoGrowthperformance of Boer goats and their F1 and F2 crosses andbackcrosses with central highland goats in Ethiopiardquo LivestockResearch for Rural Development vol 31 no 6 2019

[16] P D Allison Survival Analysis Using SAS A Practical GuideSAS Institute Cary NC USA 2010

[17] E L Kaplan and P Meier ldquoNonparametric estimation fromincomplete observationsrdquo Journal of the American StatisticalAssociation vol 53 no 282 pp 457ndash481 1958

[18] J Meyers ldquoe NEWSURV family of macros an update onthe survival plotting macroNEWSURV and an introductionto expansion macrosrdquo in Proceedings of the Pharma SUG2017 pp 14ndash17 Rochester MN USA 2017

[19] SAS Base SAS 94 Procedures Guide SAS Institute Inc CaryNC USA 94 edition 2015

[20] D Y Lin and L J Wei ldquoe robust inference for the coxproportional hazards modelrdquo Journal of the American Sta-tistical Association vol 84 no 408 pp 1074ndash1078 1989

[21] M H Al-Gaabary S A Osman and A F Oreiby ldquoCaseouslymphadenitis in sheep and goats clinical epidemiologicaland preventive studiesrdquo Small Ruminant Research vol 87no 1ndash3 pp 116ndash121 2009

[22] M W Paton S B Walker I R Rose and G F WattldquoPrevalence of caseous lymphadenitis and usage of caseouslymphadenitis vaccines in sheep flocksrdquo Australian Veteri-nary Journal vol 81 no 1-2 pp 91ndash95 2003

[23] D Abebe and T Sisay Tessema ldquoDetermination ofCor-ynebacterium pseudotuberculosisprevalence and antimicro-bial susceptibility pattern of isolates from lymph nodes ofsheep and goats at an organic export abattoir ModjoEthiopiardquo Letters in Applied Microbiology vol 61 no 5pp 469ndash476 2015

[24] P W Michael ldquoe epidemiology and control of caseouslymphadenitis in Australian sheep flocksrdquo in PhD School of

Veterinary and Biomedical Sciences Murdoch UniversityMurdoch Australia 2010

[25] R Ghanbarpour and M Khaleghiyan ldquoA study on caseouslymphadenitis in goatsrdquo Indian Veterinary Journal vol 82pp 1013-1014 2005

[26] E Alemnew E Yitagesu H Addis and A Areaya ldquoRetro-spective epidemiological study on goat disease in Debrebirhan agricultural Research center Ataye boer breedingevaluation and distribution site North Shoa EthiopiardquoBiomedicine and Nursing vol 6 no 1 pp 1ndash10 2020

[27] M H Al-Gaabary S A Osman M S Ahmed andA F Oreiby ldquoAbattoir survey on caseous lymphadenitis insheep and goats in Tanta Egyptrdquo Small Ruminant Researchvol 94 no 1ndash3 pp 117ndash124 2010

[28] B Ccediletinkaya M Karahan E Atil R Kalin T De Baere andM Vaneechoutte ldquoIdentification of Corynebacterium pseu-dotuberculosis isolates from sheep and goats by PCRrdquo Vet-erinary Microbiology vol 88 no 1 pp 75ndash83 2002

[29] W Morris F A Uzal and A Cipolla PyogranulomatousMeningoencephalitis in a Goat Due to CorynebacteriumUlcerans British Medical Journal Publishing Group LondonUK 2005

[30] T S P Tiwari A Golaz D T Yu et al ldquoInvestigations of 2cases of diphtheria-like illness due to toxigenic Corynebac-terium ulceransrdquo Clinical Infectious Diseases vol 46 no 3pp 395ndash401 2008

[31] D Weerasekera Characterization of Virulence Factors ofCorynebacterium Diphtheriae and Corynebacterium UlceransFriedrich-Alexander-Universitat Erlangen-Nurnberg (FAU)Erlangen Germany 2019

8 Veterinary Medicine International

[8] J Arsenault C Girard P Dubreuil et al ldquoPrevalence of andcarcass condemnation from maedi-visna paratuberculosisand caseous lymphadenitis in culled sheep from QuebecCanadardquo Preventive Veterinary Medicine vol 59 no 1-2pp 67ndash81 2003

[9] M W Paton A R Mercy F C Wilkinson J J GardnerS S Sutherland and T M Ellis ldquoe effects of caseouslymphadenitis on wool production and bodyweight in youngsheeprdquo Australian Veterinary Journal vol 65 no 4pp 117ndash119 1988

[10] Z Fikre and G K Abraha ldquoCaseous lymphadenitis in goatsfrom Borena Range land south Ethiopia slaughtered at Lunaexport abattoirrdquo Journal of Veterinary Medicine and AnimalHealth vol 6 no 6 pp 168ndash173 2014

[11] D Hunduma W Tigre M Wagari and F Regassa ldquoPre-liminary study on major health problems of the newly in-troduced Boer goat breed in EthiopiardquoWorld Applied SciencesJournal vol 11 no 7 pp 803ndash807 2010

[12] B Molla ldquoe health performance of imported Boer goat(Capra hircus) and their crosses with Woito-guji goat breedsin South Omo Zone South-Western Ethiopiardquo TropicalAnimal Health and Production vol 48 no 4 pp 855ndash8612016

[13] K Fekadu ldquoEthiopian seasonal rainfall variability and pre-diction using canonical correlation analysis (CCA)rdquo EarthSciences vol 4 no 3 pp 112ndash119 2015

[14] A Mustefa ldquoReproduction and survival analysis of Boer andtheir crosses with Central Highland goats in EthiopiardquoLivestock Research for Rural Development vol 31 no 10 2019

[15] A Mustefa S Gizaw S Banerjee and A Abebe ldquoGrowthperformance of Boer goats and their F1 and F2 crosses andbackcrosses with central highland goats in Ethiopiardquo LivestockResearch for Rural Development vol 31 no 6 2019

[16] P D Allison Survival Analysis Using SAS A Practical GuideSAS Institute Cary NC USA 2010

[17] E L Kaplan and P Meier ldquoNonparametric estimation fromincomplete observationsrdquo Journal of the American StatisticalAssociation vol 53 no 282 pp 457ndash481 1958

[18] J Meyers ldquoe NEWSURV family of macros an update onthe survival plotting macroNEWSURV and an introductionto expansion macrosrdquo in Proceedings of the Pharma SUG2017 pp 14ndash17 Rochester MN USA 2017

[19] SAS Base SAS 94 Procedures Guide SAS Institute Inc CaryNC USA 94 edition 2015

[20] D Y Lin and L J Wei ldquoe robust inference for the coxproportional hazards modelrdquo Journal of the American Sta-tistical Association vol 84 no 408 pp 1074ndash1078 1989

[21] M H Al-Gaabary S A Osman and A F Oreiby ldquoCaseouslymphadenitis in sheep and goats clinical epidemiologicaland preventive studiesrdquo Small Ruminant Research vol 87no 1ndash3 pp 116ndash121 2009

[22] M W Paton S B Walker I R Rose and G F WattldquoPrevalence of caseous lymphadenitis and usage of caseouslymphadenitis vaccines in sheep flocksrdquo Australian Veteri-nary Journal vol 81 no 1-2 pp 91ndash95 2003

[23] D Abebe and T Sisay Tessema ldquoDetermination ofCor-ynebacterium pseudotuberculosisprevalence and antimicro-bial susceptibility pattern of isolates from lymph nodes ofsheep and goats at an organic export abattoir ModjoEthiopiardquo Letters in Applied Microbiology vol 61 no 5pp 469ndash476 2015

[24] P W Michael ldquoe epidemiology and control of caseouslymphadenitis in Australian sheep flocksrdquo in PhD School of

Veterinary and Biomedical Sciences Murdoch UniversityMurdoch Australia 2010

[25] R Ghanbarpour and M Khaleghiyan ldquoA study on caseouslymphadenitis in goatsrdquo Indian Veterinary Journal vol 82pp 1013-1014 2005

[26] E Alemnew E Yitagesu H Addis and A Areaya ldquoRetro-spective epidemiological study on goat disease in Debrebirhan agricultural Research center Ataye boer breedingevaluation and distribution site North Shoa EthiopiardquoBiomedicine and Nursing vol 6 no 1 pp 1ndash10 2020

[27] M H Al-Gaabary S A Osman M S Ahmed andA F Oreiby ldquoAbattoir survey on caseous lymphadenitis insheep and goats in Tanta Egyptrdquo Small Ruminant Researchvol 94 no 1ndash3 pp 117ndash124 2010

[28] B Ccediletinkaya M Karahan E Atil R Kalin T De Baere andM Vaneechoutte ldquoIdentification of Corynebacterium pseu-dotuberculosis isolates from sheep and goats by PCRrdquo Vet-erinary Microbiology vol 88 no 1 pp 75ndash83 2002

[29] W Morris F A Uzal and A Cipolla PyogranulomatousMeningoencephalitis in a Goat Due to CorynebacteriumUlcerans British Medical Journal Publishing Group LondonUK 2005

[30] T S P Tiwari A Golaz D T Yu et al ldquoInvestigations of 2cases of diphtheria-like illness due to toxigenic Corynebac-terium ulceransrdquo Clinical Infectious Diseases vol 46 no 3pp 395ndash401 2008

[31] D Weerasekera Characterization of Virulence Factors ofCorynebacterium Diphtheriae and Corynebacterium UlceransFriedrich-Alexander-Universitat Erlangen-Nurnberg (FAU)Erlangen Germany 2019

8 Veterinary Medicine International