Nose Cancer (Fibrosarcoma) in Dogs

Canine neoplasms in the nasal area account for a very small number of tumors usually diagnosed. They are, however, most often of the malignant form and can be very invasive. Tumors can present with a facial deformity, can affect the teeth, and can become very debilitating. Dogs of middle age to geriatric life stage are most often diagnosed with nose cancer of the fibrosarcoma type. There does not seem to be a sex predilection, but breeds of the mesocephalic (intermediate length and width) and the dolichocephalic (long skull) type are more apt to get cancerous nasal growths.

Cancerous nasal growths can be classified as different types, with one of them being fibrosarcoma, which is named as such due to the type of cells (fibroblasts). They are soft tissue tumors and can vary greatly in their appearance and size. A fibrosarcoma of the nose is typically treated by excision.

Sneezing is one of the most predominant signs of a tissue growth in the nasal cavity though with some dogs this is a sporadic indication. Other symptoms are as follows:

• Facial asymmetry or deformity
• Nasal discharge
• Enlarged lymph nodes
• Nose bleed
• Loose teeth
• Lethargy
• Loss of appetite
• Weight loss
• Breathing changes and noises
• Eye abnormalities and discharge
• Pawing at the face
• Mucus and phlegm in the nasal passages and sinuses

Your dog may show neurological signs if the mass has become intrusive within the head.

As with many cancers, the exact cause is not easy to determine. Studies, though inconclusive, have indicated that genetics, enzyme activity and abnormalities, and environmental carcinogens (such as the breathing in of tobacco smoke) may play a part in the development of nasal tumors.

When you bring your dog to the veterinarian, it will be helpful to provide information that could help in the diagnostic process. How long the symptoms have been apparent and any behavioral changes you may have noticed are good points to mention. Also, if you have seen signs like sneezing, noisy breathing, or ocular discharge be sure to let the veterinarian know. She will want to rule out potential causes such as dental issues, fungal or bacterial infection, foreign body obstruction, or injury due to trauma. Standard diagnostic tools of complete blood count, serum chemical profile and urinalysis can give evidence of your pet’s overall health. Because nose cancer is often accompanied by bleeding, a coagulation profile may be done to verify that there is not another reason for the bleeding.

As far as determining the presence of cancer, several diagnostic tests are available.

• Lymph node aspiration, using a fine needle to take a sample of cells for analysis
• Imaging of the nasal cavity (CT scan shows bone changes and MRI defines soft tissue changes)
• Skull radiographs must be done under anesthesia
• A mass biopsy is best done after a CT scan because the location of the mass is likely known

In addition, once cancer has been identified, a thoracic radiograph could be advised to check for metastasis which could determine the treatment protocol that will be used.

Treatment for fibrosarcoma of the nose is not straightforward. Surgery is not always an option because of the difficulty that may be in excising the tumor, and the possible fact that tumor margins may be missed. Often, radiation is the option. Radiation is able to offer control of growth of the tumor and can offer a better quality of life to canines with cancer, but it is not without side effects. The side effects and the time of healing are things you must discuss with your veterinarian. Chemotherapy is sometimes offered alone or in conjunction with radiation. Palliative radiation is an option as well, and may be chosen to offer your furry family member comfort. Your veterinarian will advise you on the kindest and most appropriate therapy for your pet’s situation.

As with many types of cancer, the prognosis is often guarded to poor. It has been documented though, that the lives of some pets have been extended one to two years with cancer treatments. Realistically, it must be accepted that even with treatment, not all outcomes are positive. Studies have shown that even with a complete eradication of the tumor, recurrence is very common.