A lymphoid neoplastic disease in cattle caused by the bovine leukemia virus. Enzootic bovine leukosis may take the form of lymphosarcoma, malignant lymphoma, or leukemia but the presence of malignant cells in the blood is not a consistent finding.

The type species of DELTARETROVIRUS that causes a form of bovine lymphosarcoma (ENZOOTIC BOVINE LEUKOSIS) or persistent lymphocytosis.

Diseases of domestic cattle of the genus Bos. It includes diseases of cows, yaks, and zebus.

Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.

A group of transmissible viral diseases of chickens and turkeys. Liver tumors are found in most forms, but tumors can be found elsewhere.

The type species of ALPHARETROVIRUS producing latent or manifest lymphoid leukosis in fowl.

Excess of normal lymphocytes in the blood or in any effusion.

A progressive, malignant disease of the blood-forming organs, characterized by distorted proliferation and development of leukocytes and their precursors in the blood and bone marrow. Leukemias were originally termed acute or chronic based on life expectancy but now are classified according to cellular maturity. Acute leukemias consist of predominately immature cells; chronic leukemias are composed of more mature cells. (From The Merck Manual, 2006)