Approximately 1 percent of canine cancers involve the nasal passages or sinuses. Unfortunately, roughly 80 percent of canine nasal or sinus tumors are malignant. The majority of these cancers consist of various carcinomas -- tumors originating in the skin or organs -- while sarcomas make up approximately a third of canine nasal and sinus tumors. Sarcomas develop in connective tissue.
Sinus Cancer Symptoms
Dogs with nasal or sinus tumors usually experience discharge and bleeding from the nose, often out of just one nostril. An affected dog might constantly snort or exhibit other breathing issues. His breath will become bad. Over time, the dog's face might become distorted as the tumor grows. He might suffer from an eye discharge as the tumor affects the tear duct. The eye might also start protruding. Some dogs display neurological symptoms, such as seizures or circling, or partial paralysis.
Dogs at Risk
Although any dog can develop sinus cancer, it's more prevalent in long-nosed. medium and large breeds. The average age for a dog diagnosed with a nasal or sinus tumor is about 10 years. Males are more often afflicted than females. Dogs living in cities are more vulnerable than those in suburban or rural environments. Those animals regularly exposed to cigarette smoke, flea sprays and other contaminants, including kerosene heaters, are more likely to develop nasal or sinus tumors.
Diagnosis and Treatment
Your vet conducts blood tests, a urinalysis and a clotting profile on your dog. In order to determine the location of the tumor -- either in the nasal passages or sinuses -- your vet must X-ray your dog's head. The only way to definitely diagnose the tumor as benign or malignant is through biopsy. Just prior to the biopsy, your dog undergoes a computed tomography scan, so the vet can see the tumor in detail. The majority of dogs diagnosed with sinus tumors receive daily weekday radiation therapy for a period of three to four weeks. Some dogs might receive chemotherapy, which doesn't significantly improve survival time but does relieve certain symptoms of the disease.
Canine nasal or sinus cancer is usually diagnosed after the tumor has begun spreading. Because the sinuses are adjacent to the brain, these types of tumors often aren't good candidates for surgery. Dogs who don't receive treatment generally live about three months after diagnosis, according to Drs. Stephen J. Withrow and David M. Vail, authors of "Withrow and MacEwen’s Small Animal Clinical Oncology." Dogs who do undergo surgery live between three and six months. Those treated with radiation alone have the longest survival time, between eight and 20 months.