An outbreak of caseous lymphadenitis in dairy goats: first report of the disease in the Netherlands

An outbreak of caseous lymphadenitis in which three herds of goats were involved is described. Corynebacterium pseudotuberculosis was shown to be the causative organism. The outbreak was associated with imported goats. As this first report of C. pseudotuberculosis causing caseous lymphadenitis as a clinical entity in small ruminants in the Netherlands, clinical and epizootiological aspects as well as possible methods of control are discussed.     

An outbreak of caseous lymphadenitis in dairy goats: First report of the disease in the Netherlands

Summary

An outbreak of caseous lymphadenitis in which three herds of goats were involved is described. Corynebacterium pseudotuberculosis was shown to be the causative organism. The outbreak was associated with imported goats. As this first report of C. pseudotuberculosis causing caseous lymphadenitis as a clinical entity in small ruminants in the Netherlands, clinical and epizootiological aspects as well as possible methods of control are discussed.     

The Norwegian Healthier Goats programme – A financial cost–benefit analysis

The aim of this study was to evaluate the profitability to dairy goat farmers of participating in the Healthier Goats disease control and eradication programme (HG), which was initiated in 2001 and is still running. HG includes the control and eradication of caprine arthritis encephalitis (CAE), caseous lymphadenitis (CLA) and paratuberculosis (Johne's disease) in Norwegian goat herds.     

Seroepidemiological characterization and risk factors associated with seroconversion to Corynebacterium pseudotuberculosis in goats from Northeastern Brazil

Goat breeding in the Northeast region of Brazil plays an important socioeconomic role. However, there are significant losses caused by sanitary deficits and infectious diseases, particularly caseous lymphadenitis (CL). Although CL is considered endemic in Northeastern Brazil, a comprehensive and up-to-date study of this disease in goat herds in this region is necessary. The objective of this study was to determine the farm-level and animal-level seroprevalences for the disease and to identify the possible risk factors that characterize CL in the caprine species of five Northeastern’s states (Ceará, Piauí, Rio Grande do Norte, Paraíba, and Sergipe). A total of 2744 goat serum samples from 230 farms were collected between 2010 and 2012. The diagnosis of Corynebacterium pseudotuberculosis infection was performed using the indirect ELISA technique. Farm-level and animal-level seroprevalences were 87.8% and 30.3%, respectively, suggesting that C. pseudotuberculosis is widespread in goat herds of the Northeast region. The risk factors were as follows: absence of forage silage (odds ratio?=?5.39), not separating animals by sex (odds ratio?=?4.16) or by age (odds ratio?=?6.30), not replacing old goat breeders (odds ratio?=?7.80), and non-treatment of CL lumps prior to spontaneous rupture (odds ratio?=?10.34). This study supports the idea that caseous lymphadenitis is widely disseminated in goats from Northeastern Brazil and based on the risk factor analysis attention should be given to the need to establish adequate control measures, such as incision and early drainage of superficial abscesses, quarantine and elimination of affected animals, periodic inspection of the herd, non-introduction of infected animals, and early disposal of animals with recurrent CL.

     

Double-antibody sandwich enzyme-linked immunosorbent assay and immunoblot analysis used for control of caseous lymphadenitis in goats and sheep.

A double-antibody sandwich ELISA for detection of antibodies directed against the exotoxin of Corynebacterium pseudotuberculosis, the cause of caseous lymphadenitis (CL) in small ruminants, was developed. A concentrated exotoxin was used. For interpretation of ELISA results, these sera were tested: sequentially obtained sera of C pseudotuberculosis-inoculated goats and sheep that were monitored for 68 weeks; sequentially obtained sera from 80 goats of 3 flocks with CL; sera from 652 goats of 7 flocks without CL; sera from 160 sheep of 4 flocks without CL; and 2,265 caprine and 208 ovine sera submitted for diagnostic testing. Data regarding the infection status and history of 10,454 of the 23,302 animals were collected after testing; most of these were goats that had been part of a CL control program. Specificity and sensitivity of the ELISA were nearly 100%. Subsequently, 31,978 animals from which no data on infection status of flocks had been collected were then tested. It was concluded that the ELISA is a useful diagnostic test for CL eradication programs. Sera with doubtful or inconclusive ELISA results were examined by use of immunoblot analysis. Proteins from C pseudotuberculosis culture supernatant were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and blotted onto nitrocellulose. Six proteins with molecular mass of 68, 65, 39, 38, 31, and 29 kDa reacted with sera from goats and sheep with experimentally induced or naturally acquired infection. Immunoblot analysis was valuable in classifying sera with doubtful or inconclusive results by ELISA.     

Corynebacterium pseudotuberculosis infection in goats. II. The prevalence of caseous lymphadenitis in 36 goat herds in Northern Norway

The precalen-ce of caseous lymphadenitis was surveyed in 36 goat herds in Northern Norway. In each herd, information concerning the occurrence of the disease was obtained from the farmer. Adult animals (1 year of age or older) in 35 herds were examined for superficial swellings, and serum samples were collected from most animals in the herds. The sera were examined for antibodies to Corynebacterium pseudotuber-culosis using the bacterial agglutination test (BAT) and the hemolysis inhibition test (HIT).Gaseous lymphadenitis was diagnosed with certainty in 19 herds. Information from the farmers indicated that the disease indeed oc-curred in these herds, and that the majority had been infected with the disease for many years. The herds had apparently become infected through contact with animals from infected herds. Clinical examina-tions were carried out in 18 of these herds and superficial swellings were found in 26 % of the examined animals. The prevalence of ani-mals with lesions varied from 11 to 40 % among the herds. Of the animals in these herds, 81 % were positive in BAT and 84 % in HIT. The prevalence of positive animals varied from 26 to 99 % in BAT and 28 to 99 % in HIT. The prevalence of seropositive animals was lowest in a herd in which animals were kept separately in stalls.Caseous lymphadenitis could not be diagnosed in 16 herds. In-formation from the farmers indicated that the disease indeed seemed to be absent in 14 of these herds. These 14 herds had no history of contact with animals from herds considered to be infected. However, in the remaining 2 herds, the farmers were somewhat uncertain about the occurrence of the disease. One of these 2 herds had a history of contact with infected herds through participation in a goat “breeding circle”. Only a few of the animals were, however, seropositive and all these had low antibody titres.In 1 newly established herd, a single animal showed a high posi-tive titre in BAT only. All the other animals were negative in both tests. This particular herd consisted of animals obtained both from herds with caseous lymphadenitis and from herds in which the disease was not considered to occur.     

CASEOUS LYMPHADENITIS IN GOATS

SUMMARY Two dairy goat stud herds were surveyed for Corynebacterium ovis infection by clinical examination and serum tests using both the haemolysis inhibition and double immunodiffusion techniques for detection of C. ovis antitoxin. In one herd, of 53 goats, 11 had abscesses from which C. ovis was recorded; 33 and 29 goats were positive to the haemolysis inhibition and double immunodiffusion tests respectively. Serums from 10 and 9 of 23 kids gave reactions positive to the respective tests with 19 of the 23 kids having been born to does with demonstrable antibody. In a second herd of 57 goats 16 had superficial abscesses containing C. ovis ; serums from 34 and 45 goats gave positive reactions to the haemolysis inhibition and double immunodiffusion tests respectively. The prevalence of caseous lymphadenitis in these stud herds was a cause of economic loss to the owners through euthanasia of severely affected goats, reduced milk production and emaciation, the cost of labour and drugs for treatment, jeopardisation of income from boarding or mating with outside stock and the appearance of goats at stud shows, and sale of valuable breeding stock to local and export markets.     

Characterization of lectin-binding lymphocytes in goats with caseous lymphadenitis

Numbers of lymphoid cells bearing markers for peanut agglutinin, wheat germ agglutinin, and anti-immunoglobulin G in healthy goats and in goats with caseous lymphadenitis were determined by use of immunofluorescent techniques. Results indicated that, when compared with healthy goats, diseased goats had normal numbers of anti-immunoglobulin G-positive cells (B cells), had significantly reduced numbers of peanut agglutinin-positive cells (T cells), and had fewer cells with receptor sites for Lens culinaris agglutinin and concanavalin A. Compared with healthy goats, numbers of peanut agglutinin-positive cells in goats with caseous lymphadenitis indicated that the goats may have had a compromised cell-mediated immunity.     

High seroprevalence of caseous lymphadenitis in Brazilian goat herds revealed by Corynebacterium pseudotuberculosis secreted proteins-based ELISA

We conducted a seroepidemiological survey to determine the prevalence of caseous lymphadenitis (CLA) in goat herds in Minas Gerais state, Brazil. Serum samples were collected from goats (n = 676) from 108 rural properties in 2001, covering most of the sub-regions of this ca. 586,500 square kilometer state. Antibodies against Corynebacterium pseudotuberculosis secreted proteins were detected by an indirect enzyme-linked immunosorbent assay (ELISA). Most of the animals (78.9%) tested positive for CLA; 98% of flocks presented at least one seropositive animal. Goats managed under an extensive production system had a significantly higher seroprevalence of CLA than those in intensive and semi-intensive operations. The age distribution of the animals in the flocks affected the prevalence of this disease; however, goat breed did not. We found seropositivity against C. pseudotuberculosis to be highly prevalent in these Brazilian goat herds; consequently, appropriate management practices for the control of CLA should be implemented.     

Animal health research in the Small Ruminant Collaborative Research Support Program

Disease is a major constraint in small ruminant production systems in lesser-developed countries throughout the world. Animal health projects have been an integral part of the Small Ruminant Collaborative Research Support Program (SR-CRSP) from its inception. At the onset, these projects were oriented toward herd health care and veterinary extension activities. Later, all the projects developed a sharper focus in that they were directed to more basic studies of infectious disease. Diseases currently being investigated include caseous lymphadenitis, contagious caprine pleuropneumonia, caprine arthritis-encephalitis, ovine pulmonary carcinoma, ovine progressive pneumonia and neonatal mortality of alpaca. Continued, sharply focused studies are projected for the future to take advantage of recombinant technology in the development of multivalent vaccines.     

Serologic response and lesions in goats experimentally infected with Corynebacterium pseudotuberculosis of caprine and equine origins

Fifteen goat kids were experimentally inoculated with Corynebacterium pseudotuberculosis. Five were given a strain of caprine origin (nitrate-negative biotype) intradermally, 5 were given a strain of equine origin (nitrate-positive biotype) intradermally, and 5 were inoculated intranasally with the caprine-origin strain. Animals were monitored for 127 days. The goats given the inocula intradermally developed abscesses; those given caprine-origin strain had multiple lesions both peripherally and in visceral locations (primarily endothoracic abscesses), whereas those given the equine-origin strain had abscesses only at injection sites and draining nodes. The difference in extent of lesions could be due to biotypic bacterial differences or to the individual strains used. Intranasally inoculated goats did not develop abscesses and were essentially no different from controls. The cranial part of the respiratory tract may not be an important portal of entry for C pseudotuberculosis. Serum samples obtained monthly from all animals were subjected to the synergistic hemolysis-inhibition test, which measures antibodies to the exotoxin of C pseudotuberculosis. Animals with abscesses developed titers within 1 month of inoculation. Animals without abscesses remained seronegative. The synergistic hemolysis-inhibition test may be a reliable diagnostic assay for caseous lymphadenitis in goats.     

Prevalence of antibody to caprine arthritis-encephalitis virus in goats in the United States.

Goats from 28 states were tested for antibodies to caprine arthritis-encephalitis virus. Of 3,790 goats, 1,175 (31%) tested positive, and of 196 herds tested, 143 (73%) had 1 or more seropositive members. This prevalence, based on serum samples from all goats in the participating herds, was lower than most rates reported in other studies. Such studies were based on fewer samples, incomplete sampling of herds, or smaller geographic base. Prevalence was highest in western Pacific and northern plains regions, increased with age to 3 years, was highest among goats on family-owned farms, and was lowest in the Angora breed. Differences in prevalence was not related to gender or size of herd.     

Disease incidence in ranch and pastoral livestock herds around Lake Mburo National Park,in South Western Uganda

A longitudinal study was done to monitor incidence of livestock diseases in ranch and pastoral herds around Lake Mburo National Park, in South-western Uganda with a high level of wildlife (impala and zebra) and livestock (cattle and goats) interactions. East Coast Fever (ECF), abortions, helminthosis and starvation due to drought were major livestock disease problems encountered. ECF was a major disease affecting mainly calves, causing mortality both in ranch (8.5%) and pastoral (8.2%) herds. Meanwhile, drought was a more serious in pastoral than ranch herds (p < 0.05), killing 28.5 % and 5.8% of adult female cattle in respective production systems. Other endemic diseases found and controlled by vaccination were FMD, CBPP and blackquarter. In both cattle and goats helminthosis was causing mortalities, 3.3% and 0.8% among calves in pastoral and ranches respectively; and 4.8% and 6.9% among kids and sub-adult goats respectively. Many cases of abortions occurred among pastoral herds. In conclusion, the disease incidence among livestock was the same or relatively low as compared to other areas without wildlife.     

Johne's Disease (Paratuberculosis) in Goats: A Report of Eight Cases in Quebec

Johne's disease (paratuberculosis) is reported in eight goats. Clinical signs were mainly those of a chronic wasting disease which lead to emaciation, severe weakness, prostration and death. Soft pasty stool and/or profuse diarrhea were observed only after several weeks of illness, in the terminal stages of the disease, in six of the eight goats. Gross lesions were characterized by emaciation and mesenteric lymphadenopathy with more or less extensive areas of caseous necrosis and calcification. Gross lesions in the intestinal tract were limited to a mild thickening and corrugation of the mucosa of the distal small intestine, cecum and proximal parts of the colon in three of the affected animals. Caseous necrosis of Peyer's patches and ulceration were observed in two goats when small tuberculoid nodules were present in the liver of another one. Histologically, the intestinal lesions were characterized by accumulations of large foamy or vacuolated macrophages in the intestinal mucosa. Lesions were usually mild and multifocal in the proximal and middle parts of the small intestine, more diffuse and severe in the distal jejunum, ileum and proximal parts of the colon. Several of the macrophages infiltrated in the intestinal mucosa and mesenteric lymph nodes were packed with acid fast bacilli. Observations made on these animals stress the importance of a careful histological examination of the intestines and mesenteric lymph nodes of adult goats submitted to necropsy because of a chronic wasting disease.     

Evaluation of the humoral and cellular immune response to different antigens of Corynebacterium pseudotuberculosis in Canindé goats and their potential protection against caseous lymphadenitis

Corynebacterium pseudotuberculosis is the etiologic agent of caseous lymphadenitis, a disease that affects goats and sheep, and can cause severe economic losses. In this study, four different antigenic extracts were obtained from the attenuated strain T1, which was isolated in the state of Bahia (Brazil). Forty-four Canindé breed goats were divided in five groups, each receiving a different antigen solution and saline buffer as a control. The humoral response was monitored through the identification of specific IgG by indirect ELISA and Western Blotting, and the production of IFN-gamma was followed in order to observe the activation of cellular response. After twelve weeks of antigen inoculation, the animals were challenged with 2 x 10(5)CFU of a wild strain, also isolated in Bahia, and necropsy was performed on all animals twelve weeks afterwards. It was observed that the attenuated bacteria gave a protection of 33.3%, in addition to the weak humoral response elicited. Animals inoculated with secreted antigen associated with Freund's incomplete adjuvant and oligodeoxynucleotide containing unmethylated CpG dinucleotides (CpG ODN) showed a strong humoral response, but this inoculation could not prevent the spread of challenge bacteria in the majority of animals. These results demonstrate the immunogenic potential of the attenuated T1 strain in the development of a vaccine against caseous lymphadenitis in goats.     

State-of-the-art review of goat TSE in the European Union, with special emphasis on PRNP genetics and epidemiology

Scrapie is a fatal, neurodegenerative disease of sheep and goats. It is also the earliest known member in the family of diseases classified as transmissible spongiform encephalopathies (TSE) or prion diseases, which includes Creutzfeldt-Jakob disease in humans, bovine spongiform encephalopathy (BSE), and chronic wasting disease in cervids. The recent revelation of naturally occurring BSE in a goat has brought the issue of TSE in goats to the attention of the public. In contrast to scrapie, BSE presents a proven risk to humans. The risk of goat BSE, however, is difficult to evaluate, as our knowledge of TSE in goats is limited. Natural caprine scrapie has been discovered throughout Europe, with reported cases generally being greatest in countries with the highest goat populations. As with sheep scrapie, susceptibility and incubation period duration of goat scrapie are most likely controlled by the prion protein (PrP) gene (PRNP). Like the PRNP of sheep, the caprine PRNP shows significantly greater variability than that of cattle and humans. Although PRNP variability in goats differs from that observed in sheep, the two species share several identical alleles. Moreover, while the ARR allele associated with enhancing resistance in sheep is not present in the goat PRNP, there is evidence for the existence of other PrP variants related to resistance. This review presents the current knowledge of the epidemiology of caprine scrapie within the major European goat populations, and compiles the current data on genetic variability of PRNP.     

A comparison of four serological tests for the diagnosis of caseous lymphadenitis in sheep and goats

A double antibody sandwich ELISA (ELISA A) developed for the detection of Corynebacterium pseudotuberculosis infection in sheep and goats was modified to improve its sensitivity. To establish the sensitivity and specificity of this modified ELISA (ELISA B), sera from 183 sheep and 186 goats were tested using ELISAs A and B. Comparison was also made with two further ELISAs (C and D) developed in Australia that, respectively, detect antibodies to cell wall antigens or toxin.ELISA B had the best performance of the four tests. Its specificity was 98+/-1% for goats and 99+/-1% sheep. Its sensitivity was 94+/-3% for goats and 79+/-5% for sheep. ELISA B will now be tested for use in caseous lymphadenitis eradication and control programmes in The Netherlands. It will also be used in experimental studies of CL in Scotland.     

A simplified double immunodiffusion technique for detection of Corynebacterium ovis antitoxin

A method is described for obtaining yields of Corynebacterium ovis exotoxin sufficiently high to allow use of unconcentrated supernatant and serum as the reactants in a double immunodiffusion test. C ovis supernatant with a haemolytic titre or rabbit dermal necrosis titre of 1:16,394 or greater produced readily detectable precipitation lines with specific antitoxin in the range of concentrations commonly found in sera from cases of natural C ovis infection. When used as a diagnostic screening test, sera from 32 confirmed cases of caseous lymphadenitis in sheep and goats were positive whereas sera from 16 sheep free of caseous lymphadenitis were negative. Sera from 10 out of 16 kids which had been suckled by mothers from an affected flock of goats were positive.     

A seroepidemiological investigation of Corynebacterium pseudotuberculosis infection in sheep flocks in southern Norway

Corynebacterium pseudotuberculosis causes caseous lymphadenitis, a disease primarily affecting sheep and goats which occurs as a chronic infection characterized by suppurative lymphadenitis (Lovell 1959, Marsh 1965, Jubb & Kennedy 1970, Ayers 1977, Addo & Eid 1978). The disease has an insidious nature and a high prevalence, resulting in large economic losses due to condemnation of carcasses and organs at slaughter (Turner 1973).     

Prevalence and distribution of caseous lymphadenitis in feral goats

A total of 2,920 feral goats from pastoral areas of Western Australia were examined and the prevalence of caseous lymphadenitis was estimated to be 7.8 +/- 0.9% in goats presented for slaughter. Head, body and visceral lesions were present in 49.3%, 46.7% and 12.3% of affected goats, respectively. A comparison with previously reported data from sheep has been made and significant differences are discussed. Lung lesions were relatively uncommon in goats, whereas the distribution of carcase lesions was similar between the species. Multiple lesions appear to be less common in goats than in sheep.