Causative agent
- Corynebacterium pseudotuberculosis
Differential diagnosis
- Actinomyces pyogenes infection
- Melioidosis
- Actinobacillosis
- Tuberculosis
1. History examination
- A chronic endemic disease in large sheep and
goat population, sporadic in horse and cattle
- Herd history of introduction of imported goat
2. Clinical examination
- Superficial lymph nodes enlargement and abscess
formation
- Abscess or scar tissue under the ears from healed
abscess
- Morbidity rate up to 20% in adult goat
3. Necropsy
- Abscess has a toothpaste like consistency pus and
thick fibrous capsule
- Abscess in the internal organ : lung, liver, spleen
and kidney
- Abscess lesion in the prescapular, precrural,
popliteal, bronchial and mediastinal lymph nodes
4. Histopathological observation
- Central mass of laminated caseous necrosis in
lymph node surrounded by a wall of connective
tissue
|
- Colonies of C. pseudotuberculosis are discernible
in the necrotic tissue and in the lumina of capillaries
in the wall of abscess
5. Bacterial isolation
Specimen : superficial lymph node, lung, liver,
spleen, kidney, pus or absces
Medium : Blood agar contains 5-10% cattle
blood, incubate aerobically at 37°C for
3-4 days
- Colony : small, translucent colonies and
becoming opaque, dry and cream color
in 3-4 days, β-hemolysis on blood agar,
Gram positive, pleomorphic or short
rod
| Table: Biochemical characteristic of C.pseudotuberculosis |
urease |
+ |
gelatin liquefaction |
- |
glucose |
+ |
maltose |
+ |
sucrose |
- |
mannitol |
- |
xylose |
- |
|
|
Control and treatment
- Eradication of sick animal
- Treatment with ampicillin, erytromycin, gentamicin
or tetracycline
- Use of new yards each year
- Elimination of wire, tin that likely to cause skin
wounds
|
