Rhinoscopic Appearance and Clinical Features of a Nasal Transmissible Venereal Tumor in a Dog

A 2-year-old male neutered mixed breed dog was referred for evaluation of left-sided unilateral epistaxis and mucoid discharge following adoption from Mexico 2 months prior to presentation. Computed tomography (CT) showed soft tissue that filled the entirety of the left nasal passage with mild turbinate loss. Subsequent rhinoscopy revealed multifocal patches of discrete, white, wispy, vascularized abnormal tissue in the left nasal cavity. Cytology and histopathology procured with rhinoscopic-guidance were suspicious for transmissible venereal tumor (TVT). Confirmation of a TVT diagnosis was made with polymerase chain reaction for the long interspersed element inserted upstream of the c-myc gene. The dog was treated with 4 cycles of vincristine (0.5 mg/m², IV, once every 7 days) with complete and sustained resolution of clinical signs shortly after the third cycle. Nasal TVT in dogs is an uncommon presentation of a neoplasm that primarily results in genital or oral lesions. There is a void in the veterinary literature regarding the rhinoscopic appearance, as well as limited clinical descriptions of nasal TVT. Therefore, the objectives of this report were to provide a detailed description of the rhinoscopic appearance of a canine nasal TVT, in addition to clinical features, diagnostic findings, CT imaging, and successful therapeutic management.