Extragenital disseminated transmissible venereal tumour in a 4‐month‐old puppy

Abstract A 4‐month‐old, crossbred, prepubertal, male puppy with a 2‐month history of reduced appetite, severe dyspnoea and a cough refractory to antimicrobial and antifungal therapy was referred for veterinary examination. Physical examination revealed tachypnoea, restrictive breathing, mild generalised lymphadenomegaly, and nodules in the subcutis and conjunctiva. The complete blood count showed mild neutrophilic leukocytosis. All lung lobes were severely and diffusely radio‐opaque in lateral thoracic radiographs. A neoplastic round‐cell population consistent with canine transmissible venereal tumour was seen on the cytology of fine‐needle aspirates of conjunctival nodules and nasal exudates. The case was diagnosed as extragenital disseminated canine transmissible venereal tumour and vincristine sulphate (0.5 mg/m2 intravenously every week, approximately four to six doses until complete remission of clinical signs) was prescribed. After the third dose, clinical signs and pulmonary radio‐opacity reduced markedly. However, the owner stopped the treatment before complete remission, and the puppy died at the age of 6 months.