It is described in case of a female canine of 7 years of age, Labrador breed resident rural area of Florencia Caquetá Colombia, whose reason for consultation was a circumscribed lesion in the right hind limb, hyperkeratosis of pulp and truffle, hypotrichosis and long nails. Within the presumptive diagnosis leishmaniasis is suspected. A complete clinical examination, followed by complementary tests such as hemogram, Hemoparasites, cytology, coprological, uroanalysis, deep skin scraping, blood chemistry, and complementary biopsy examination were performed, which resulted in malignant round cell tumor being considered a suspected lymphoma. To the deplorable state of health and well being it was decided to establish euthanasia and to carry out histopathological analysis, for determination of definitive diagnosis. The alterations to the necropsy of greater affectation were placed in the liver and kidneys, and like definitive diagnosis the histopathology was a lymphoma.