The article reports epidemiological data, clinical signs, and laboratory and pathological findings in 24 cattle with enzootic bovine leukosis observed in the Clinic of Garanhuns, at the Federal Rural University of Pernambuco. The 24 cases represented 0.5% of 4,758 cattle examined from 2000 to 2010. The disease affected 22 (91.7%) females and two males. Twenty one of the animals were dairy (six Holstein, 13 girolando, one Brown Swiss and one Jersey), and three were for meat production (Nelore). Twenty three animals were 3-8 years of age and one was younger. All were raised in confinement or semi-confinement. All animals showed enlarged superficial lymph nodes. Other frequent clinical signs were hyporexia, decreased milk production, progressive weight loss, dehydration, hypomotility of the fore stomachs, and altered scant feces. Exophthalmia, dyspnea, and enlarged uterus were observed with less frequency. Leukocytosis (mean of 34,082 leukocytes/µL) with lymphocytosis (21,814 lymphocytes/µL) and neutrophilia (10,906lymphocytes/µL) was observed in the white blood count. Thirteen bovines were necropsied and 11 were slaughtered. Gross lesions were observed on the superficial lymph nodes of all animals necropsied. Six had lesions in the mesenteric lymph nodes, six in the gut, three in the abomasum, two in the uterus, one in the heart, one in the rumen, one in heart, and one in the liver. Due to the importance of enzootic bovine leukosis it is necessary for the farmers to introduce animals free of the disease and to establish a strict health policy for its control.
Enzootic bovine leukosis; leukemia; lymphocytosis; neoplasm
