Leukaemia:
- It is malignant state of leucopoietic disorder characterized by leucoproliferative changes in bone marrow along with appearance of abnormal premature leukocytes in peripheral circulation.
- It is typically known as “blood cancer”.
- It is recorded in dog, cat, pig, horse, cattle and sheep.
- Lymphoma is common in large animals.
- Bovine leukemia/ lymphosarcoma occurs as 4 distinct clinical case in cattle:
- Juvenile multicentric lymphosarcoma: It occurs at birth or in early life. It is multicentric and commonly involves bone marrow and lymph nodes.
- Thymic lymphosarcoma: It develops in cattle from 3 months to 2 years of age. It involves thymus, occasionally spreads to other lymph nodes and rarely infiltrates other organs.
- Cutaneous lymphosarcoma: It occurs primarily in cattle of 1-3 years of age.
- Adult multicentric lymphosarcoma: Bovine viral leukosis
Etiology:
- Genetic factor
- Viral causes is possible
- Chemical exposure
- Excessive exposure to radiation