The subject of this study was a 4-year-old, Kangal breed, male dog, brought to the Fırat University Animal Hospital Surgery Department with the complaint of difficulty in breathing and epistaxis (Protocol no: 150797). Samples from both mass and nasal discharge were sent to Pathology Department for biopsy due to clinical, radiographic and tomographic examinations of the patient with bilateral swelling on the nasal cavity below the medial angle of both eyes. The mass that completely covered the dog's nasal cavity leading to difficulty in breathing were cleaned operatively. In the histopathological examination of the mass taken from the nasal cavity operatively; hyperchromatic tumor cells with vesicular appearance, whose nuclei were very large compared to cytoplasm, were detected. The dog diagnosed with transmissible venereal tumor (TVT) received chemotherapy using vincristine sulfate for 6 weeks. Although it was observed that the clinical symptoms decreased significantly after 6 weeks of treatment, it was stated that the disease relapsed 2 months after the treatment. In this case report, we aimed to report the clinical, radiological, tomographic and histopathological findings of the TVT case, which is rarely encountered in the intranasal cavity, and to report the outcome of the treatment.