Transmissible venereal tumor (TVT) is a coitally transmitted tumor of dogs with widespread distribution. The present study describes the occurrence of the primary oral and nasal TVT in a 10-year-old, female, mix-breed dog. The case was presented with a history of anorexia, inability to swallow and dyspnea. Clinical examinations revealed the emaciation, muzzle deformity due to the presence of a friable, fleshy, cauliflower-like mass in the oral cavity and submandibular lymphadenopathy. TVT was diagnosed based on histopathological findings. The dog was discharged with therapeutic intervention with vincristine. Unfortunately, the case died before readmission because of the progressive worsening of the general condition. Our findings highlight the need for considering TVT for the differential diagnosis of the extragenital masses in dogs.