Causative aent
- BL virus, family Retroviridae
Differential diagnosis
- Tuberculosis
- Actinobacillosis
1. History taking
- Most common in cattle, usually 4-8 years of age
- Transmitted by contaminated equipment, insect
vectors play an important role
2. Clinical examination
- Weight loss
- Decreased milk
- Decreased appetite
- Anemia
- Muscular weakness
- Tumor development
- Enlargement of visceral lymph nodes
3. Hematology
- Elevated blood lymphocytes and/or presence of
abnormal lymphocytes in blood
4. Serological test
Specimen : serum
Method : AGID test
|
5. Necropsy
- Firm white tumor masses in any organs
- Affected lymph nodes may be enormously
enlarged and composed of both normal and
neoplastic tissues. The latter is firmer and whiter
than normal lymphoid tissues and often surrounds
foci of bright yellow necrosis
6. Histopathological observation
- Complete loss of lymph node architecture which
is replaced by uniform sheets of cells (mostly
lymphoblast)
- Infiltration of excess lymphocytes and
lymphoblasts into non-lymphatic tissues
Control
- Animal testing (quarterly)
- Control of insect vectors
|
