ALABAMA A&M AND AUBURN UNIVERSITIES Caseous Lymphadenitis (CL) in Goats and Sheep UNP-0085 Introduction Caseous Lymphadenitis (CL) is a chronically infectious dis- ease of sheep and goats that is caused by the bacterium Corynebacterium pseudotuber- culosis. Prevalent on all conti- nents throughout the world, CL causes ulcerative lymphadeni- tis in horses and superficial ab- scesses in bovines, swine, rab- bits, deer, laboratory animals, and humans. This zoonotic disease (a disease transmitted from animals to humans) is usually underestimated be- cause CL is not a reportable disease in many countries, including the United States. Some economic losses due to CL are caused when breed- Figure 1. CL abscess on goat. ing stock is no longer mar- ketable, when carcasses are soil of semi-arid environments 15-50%. CL abscesses are condemned due to internal for up to two years. more frequently found in older abscesses, when animals die, animals, four years or older. or when abscesses devalue The C. pseudotuberculosis Does and ewes can transmit animal hides. bacteria enters the body of an CL to kids and lambs through animal or a human through the milk if a CL abscess if Diagnosis, Prevention, the skin, by ingestion or found in the mammary gland. Treatment & Biosecurity inhalation, or by coming in Measures contact with contaminated Upon infection, C. pseudotu- equipment, facilities, pastures, berculosis will multiply and The primary mode of infection and feed and water troughs spread throughout the body is direct contact with pus or where a herd may congregate. via the bloodstream. Sub- the secretion from abscessesARCHIVE Herd mates that come into sequently, lymph nodes and that contain the C. pseudo- direct contact with a ruptured internal organs including the tuberculosis bacteria. The CL abscess can also spread the lungs, kidney, and liver be- bacteria can exist in contami- infectious bacteria from animal come infected and can develop nated soil for a long period of to animal. abscesses. The spinal cord can time. In a study conducted by also develop CL abscesses. scientists at the Brazilian Agri- Sheep and goats can be in- Once infected an animal is cultural Research Corporation fected at any time in their life- considered to be a carrier for (EMBRAPA), the C. pseudotu- time, and the morbidity rate in life. The period of incubation, berculosis was found in the herd can reach as high as the time between the initial www.aces.edu/urban infection and the appearance of physical signs, can vary from 2 to 6 months. However, some animals within a herd appear to be very resistant to this disease. They may be infected with the CL bacteria, but not develop the disease. Clinical Signs The first usual indication of CL infection is the presence of an external abscess visible behind the ears, beneath the jaw or Figure 2. A goat with a CL Figure 3. Drain pus from neck, on the shoulders, or in abscess on the body surface abscess using a cross “+” cut. the rear flank region. Abscesses may also appear between the When you suspect CL, confirm • Completely drain the hind legs where a scrotal sac the presence of the C. pseu- abscess of its content; a or udder attaches. Internal dotuberculosis microorganisms large amount of pus with abscesses are detectable only by submitting a sample of the the consistency of tooth- through necropsy, an examina- abscess content to a diag- paste may appear. You tion after the animal is dead. nostic lab for analysis. If the may wish to collect some Unfortunately, it is the inter- laboratory result is positive, of the pus with a new sy- nal abscesses that are fatal, then CL is deemed responsible ringe for submission to a whereas external abscesses are for the abscess. the ones generally responsible diagnostic lab for pathogen isolation and identification. for disease transmission. Sheep Treatment are more prone to internal There is no cure for CL. How- abscesses and goats are more ever, CL abscesses must be prone to external abscesses. treated to prevent ruptures If an animal is experiencing and further contamination of chronic weight loss, it may be other animals and environ- carrying internal CL abscesses ments. If you have an animal on vital organs. that develops an abscess: Diagnosis • Immediately isolate the Producers must be aware that animal from the herd. not all abscesses or cases of • Place the infected ani- chronic weight loss in sheep mals on a concrete floor and goats are associated with Figure 4. Completely drain the or other surface that will abscess CL. The diagnosis is based on make disinfecting easier clinical signs detected by sight to avoid spreading the CL and by physical examination. microorganism. The CL abscesses range from • Wear gloves when draining firm to soft swelling, and some abscesses to avoid con- are well-defined with rounded tamination. The abscess is shapes on the surface of the about to rupture when it animal’s body. CL abscessesARCHIVE has lost hair. typically contain pasty thick • Use a disposable scalpel to yellow-green pus with a foul cut the surface of the ab- odor. Internal abscesses can- scess and drain it before it not be seen except by X-ray, a ruptures on its own in the biopsy, or during a postmortem field. examination. Serologic tests Figure 5. Wash the abscess • Create a cross cut (+) to cavity. are available but their reliability better drain an abscess. is questionable. 2 Alabama Cooperative Extension System • Wash the resulting abscess isolated from a specific herd) • Avoid purchasing animals cavity thoroughly with are another source of available with visible abscesses or ab- hydrogen peroxide, then immunization in sheep and in scess scars. Examine males flush it with an iodine solu- goats. However, a reputable before introducing them to tion. certified laboratory must pro- the doe herd. A male with • Keep the infected animal duce the vaccine. Before using erupted abscess can con- from the rest of the herd an autogenous vaccine, test it taminate the females. until the abscess is com- in several animals for adverse • Avoid giving injections in pletely healed. side effects. Goats seem to be the shoulder region where • Disinfect the area where more sensitive to the side ef- an injection-site reaction the animals with the ab- fects of these types of vaccines. can be confused with a CL scesses were housed. abscess. Use a clean needle • Keep records of abscess Biosecurity/Biocontainment with each animal to prevent cases. Measures the spread of C. pseudotu- • Incinerate gloves, napkins, • There is not an effective berculosis from asymptom- and lining material imme- treatment for CL. Antibiot- atic carriers to non-infected diately after use. ics are ineffective. How- animals. This would be of ever, certain management particular concern with the The control of the CL disease practices can help to mini- use of automatic syringes. by vaccination remains contro- mize the impact of CL on Other microorganisms such versial although toxoid vac- the herd or flock. Conduct as Arcanobacterium (Actino- cines are now commercially frequent visual examina- myces) pyogenes can enter available in some countries. A tions of the herd and note via animal skin the same vaccine for sheep is commer- the presence of abscesses. way CL microorganisms cially available in the United This may require a closer enter, and cause abscesses. States. This vaccine is made inspection in wool sheep Using non-sterile needles with killed germs and seems and fiber goat breeds where can cause infection at injec- to be effective in decreasing long course hair or wool can tion sites. the incidence and severity of hide abscesses. The same • Always disinfect equipment the disease in sheep herds. is true of long-eared goats such as ear taggers, tattoo- However, the vaccine is not such as Boer and Nubian ing needles, hoof trimmers, approved for use in goats. goats where submandibular or wool shears that might Autogenous vaccines (vaccines abscesses can be hidden break the skin of animals made from bacteria strains under the ears. when used. Shearing equip NOTE ON FORMALDEHYDE TREATMENT: Although formaldehyde is effective in treating abscesses it can be caustic and irritant to the skin, mucosa membranes, and lungs. Formaldehyde is toxic, can be diffused through the skin to other organs, and has an accumulative effect in the goat’s body. Formal- dehyde is also a carcinogenic ARCHIVEagent to humans and is not allowed in animals, including those consumed by humans. Some producers have reported losses of animals after the inoculation of formaldehyde in the treatment of CL abscesses. Formaldehyde can be found in the meat and milk after being infused in abscesses. Figure 6. Internal CL abscess in goat liver and lung. Caseous Lymphadenitis (CL) in Goats and Sheep 3 ment is of special concern References as a hidden abscess might be ruptured during shear- Alves, F. S. F., Pinheiro, R. R., & Oliveira, A. A. da F. (2004, December). Im- ing. plicações do uso de solução de formol em abscessos, para o controle da Linfadenite caseosa. Embrapa Caprinos, Documentos, 52. Retrieved May 16, • Cull infected animals from 2012, from http://www.infoteca.cnptia.embrapa.br/bitstream/doc/46290/1/ the herd to help reduce the FL16852004.pdf risk of CL infection. • Consider maintaining a Ayres, J. L. (1977). Caseous lymphadenitis in goats and sheep: A review of diagnosis,pathogenesis, and immunity. Journal of the American Veterinary closed herd. Medical Association, 171(12), 1251-1254. Conclusion Batey, R. G. (1986). Pathogenesis of caseous lymphadenitis in sheep and goats. The Australian Journal of Experimental Biology and Medical Science, 63(9), 269-272. Caseous Lymphadenitis or CL is of great economic importance Brown, C. C., Olander, H.