Nasal tumors in dogs
Tumors of the nasal cavity and nearby sinuses account for about 1 to 2 percent of tumors in dogs. Most nasal tumors occur in large-breed dogs older than 8. Most nasal tumors are malignant or cancerous. The cause of these tumors is unknown. There are multiple tumor types, including primary tumors arising from the tissues within the nasal cavity, and secondary tumors that invade the nose, especially from the tissues around the nose.
Most signs are very subtle initially, and the tumor can be present in the nasal cavity or sinuses for months before any abnormalities are seen. The first abnormality that occurs is a bloody discharge from one nostril only. If your dog has a bloody discharge from one nostril, then take it to your veterinarian for an immediate exam. Open-mouth, noisy breathing is common if the nasal cavity is obstructed.
Tumors may be suspected in animals with chronic nasal discharge unresponsive to symptomatic therapy. X-rays of the head may demonstrate changes in the nasal cavity or sinuses that are compatible with the tumor. Occasionally, chronic inflammation and infection can lead to similar radiographic signs. Definitive diagnosis and determination of tumor type require a biopsy. Additional tests, such as laboratory tests and chest X-rays, may be recommended to rule out other nasal diseases that cause similar signs and to ensure that cancer is not present in other organs.
Radiation therapy alone can control some nasal tumors in the dog, depending upon their location and extent. Surgery has not been proven to be superior to radiation therapy alone. Chemotherapy is not very effective in most tumors except for lymphoma. The chemotherapeutic drug cisplatin can help alleviate some signs related to nasal tumors, such as nasal discharge, sneezing and nosebleeds, for varying periods of time.
Prognosis is variable with nasal tumors. With radiation and cisplatin medication, the average survival time is 474 days. Spread of most nasal tumors to other tissues is rare. Because of the dog’s marked discomfort and its breathing, and the difficulty and expense of radiation therapy, many dogs are euthanized shortly after clinical signs occur.
Dr. Karsten Fostvedt is a veterinarian at St. Francis Pet Clinic in Ketchum.