Enzootic bovine leukosis: clinical and therapeutic aspects

Abstract

Leucosis is a chronic disease, described by the manifestations of tumors and lymphadenopathy. Contamination occurs horizontally, through blood-sucking insects and the shared use of needles, and vertically, through the transplacental route. Not all animals manifest clinical symptoms, which may vary depending on the location of the tumors. The study was based on a case report of a multiparous Holstein cow, with signs of anorexia, apathy, and decreased food intake. Confirmation occurred through the unfavorable evolution in the treatment of other clinical suspicions such as pneumonia and bovine parasitic sadness, combined with the positive serological diagnosis for leukosis. In addition, there was suspicion of abomasal displacement and ultrasonography was
performed, which revealed a tumor mass attached to the abdominal cavity. Due to the unfavorable prognosis, euthanasia followed by necropsy was chosen. Macroscopically, renal tumor, presence of hepatic cysts, infarcted lymph nodes, and abomasum with thick and hardened mucosa were evaluated, and microscopically, lymph nodes with loss of cortico-medullary structure, dense and with infiltration of neoplastic lymphocytes were observed. It is concluded that the incompatibility with the maintenance of animal well-being and productivity, as well as the high prevalence in herds, demonstrate the need for disease control and eradication programs in Brazil.