Enzootic/viral bovine leukosis or also called bovine leukemia, is a disease caused by a virus (retrovirus), which causes various signs in the animal, with malignant neoplasms in the lymphatic tissue as its main characteristic. Normally, the cases show no specific signs, but have a decrease in milk production, low weight gain and reproductive problems. This document will explain two clinical cases found in El Totumo, located in the department of Tolima, the first is a 6-year-old Holstein x Gyr bovine, where it showed some not very specific signs of Leucosis, case 2 is a 14-year-old white Brahman female, in which a necropsy was performed and different samples were sent to obtain the most accurate diagnosis of the cause of death of the bovine. Currently there is no treatment or vaccination that is efficient against this virus. It is essential to identify the disease in order to eradicate it in the animal herd and thus, to be able to avoid different losses and reduce its spread.