Mesotheliomas are rare in animals but occur spontaneously in many different species, including cattle, dogs, cats, swine, and horses (1,2), as well as in rats (3), blue foxes (4), and goats (1). In the bovine species, these tumors are more frequently observed in calves than in adults (1,2) and are considered to be congenital in young animals. Mesothelial tumors can take 2 different histologic p...

The purpose of this study was to evaluate cytologically the bone marrow (and peripheral blood) of adult laying hens affected with lymphoid leukosis. Diagnosis of the neoplasm was made on the basis of clinical history, signs and symptoms and pathology. Only histologically confirmed cases were included in the study. Examination of blood smears revealed +2 heterophil toxicity and the presence of l...

Standard avian myeloblastosis virus (AMV), BAI strain A, causes myeloblastosis, osteopetrosis, lymphoid leukosis, and nephroblastoma in chickens. In this investigation, several leu kosis viruses of subgroups A and B were isolated (rom standard AMV and characterized. A subgroup A virus derived from an AMV-induced lymphoma of a Japanese quail was isolated, and it induced a high incidence of osteo...

BACKGROUND Although several attempts have been made to control enzootic bovine leukosis (EBL) at the local level, a nationwide control program has not been implemented in Japan, except for passive surveillance. Effective control of EBL requires that the transmission routes of bovine leukemia virus (BLV) infection should be identified and intercepted based on scientific evidence. In this cross-s...

In Argentina, bovine leukaemia virus (BLV) infection is common in dairy herds. The country currently has a National Voluntary Control Programme but relatively few farms have enrolled. However, there is increased interest from authorities and farmers to implement regional compulsory programmes but there is scarce quantitative information of the transmission of BLV in cattle herds. This informati...