Nasal Cancer in Dogs

Nasal cancer in dogs is more commonly found in older canines.  It is also more likely to occur in medium to large dogs with long noses (Greyhound, German Shepherd, and Husky).  Researchers are uncertain why it occurs most often to long nose dogs.  A possible answer is that there is a larger area within a longer nasal cavity being exposed to inhaled carcinogens.

Unfortunately, because the growth is inside the nasal cavity (hidden from sight), nasal cancer is not usually diagnosed in the early stages.  If your dog is showing symptoms of nasal cancer he should be seen by a veterinarian as soon as possible.

Nasal cancer is a malignant growth within the nasal cavity resulting from the division of abnormal cells.  Nasal cancer in dogs is a rare occurrence; it composes 2.5% of canine tumors.  Out of that 2.5% of dogs with nasal tumors, 80 % are diagnosed to be malignant (cancerous).

Symptoms may be different depending on the location and size of the growth.  Symptoms may include:

• Mucus or pus nasal discharge
• Nose bleeds
• Difficulty breathing
• Weight loss
• Bad breath
• Sneezing blood
• Loss of smell
• Paws at face
• Depression
• Lack of appetite 
• Displays pain when area is touched
• Ocular discharge
• Loose teeth
• Deformed palate
• Facial deformity
• Enlarged lymph nodes
• Swelling eye protrusion
• Tumors close to the brain may cause seizures and behavior changes

Types

• Sarcomas - Grow on the skin and subcutaneous connective tissues (muscle, cartilage, fat and nerves)
• Fibrosarcoma - Slow growing derived from fibrous connective tissue.
• Osteosarcoma - Bone cancer is very aggressive and can spread quickly to other parts of the body.
• Lymphoma - Originates in the lymphocyte cells (white blood cells)

Cancer is a disease resulting from the division of abnormal cells.  The exact cause of the nasal cancer in dogs may be from:

• Being exposed to secondhand smoke
• Pollution from industrial factories
• Genetics
• Breathing in carcinogens (paints, chemicals, insecticides)
• Preservatives and dyes in his diet

After discussing the recent health history of your pet, the veterinarian will look for clinical signs related to the symptoms you have described; this will include looking at your dog’s teeth and gums in order to rule out a dental issue. The veterinarian may palpate your dog’s face, muzzle and nose area.  If your canine has a nasal or ocular discharge, the doctor may take a mucus sample.  The sample is then examined under a microscope and checked for abnormal cells. The veterinarian may suggest a complete blood test and a chemistry panel test.

He may want to have x-rays taken of the dog’s skull.  If the x-rays determine a mass is present, the doctor may schedule a magnetic resonance imaging (MRI) appointment for the patient. The dog will need general anesthesia for the procedure. While under sedation a biopsy may also be taken; a biopsy needle is inserted into the tumor to retrieve tissue cell samples. A pathologist will examine the biopsy for cancer cells.

If your companion is diagnosed with cancer the veterinarian may refer you to a veterinary oncologist.  The oncologist will discuss in detail what the best medical options are for your dog.  Usually, surgery to remove the mass is recommended. Lymph node aspiration may be suggested to evaluate if the cancer has spread.  After surgery, radiation and chemotherapy may be recommended.  Radiation therapy is typically administered in 10 to 18 sessions over a 2 to 4 week span.  The specific chemotherapy medications will depend on the type of cancer the patient was diagnosed with.  

There are side effects to radiation and chemotherapy.  Your dog may experience inflammation of the oral cavity, eye dryness, shedding of the skin, and nausea.  If the patient is not eating, a short term feeding tube may need to be inserted. Additionally, radiation therapy may cause later complications such as cataracts, eye uvea and blindness. 

The patient may be prescribed an analgesic along with nonsteroidal anti-inflammatory drugs such as Tramadol or opioids, antibiotics and anti-nausea medication.

Dogs that are not treated for nasal cancer may only have a few months of life.  Dogs that do receive treatment may extend their lives for several years.  

Patients that undergo surgery will need to wear an E-collar until the sutures are removed.  The surgeon will provide you with post-operative instructions. While the dog is getting radiation therapy and chemotherapy, he may be lethargic and depressed. Dogs may not understand what is going on with their body but they do understand and respond to love and care. It is important that the owner remains strong and supportive for his pet companion. The side effects will subside once the treatment sessions end. Follow-up visit will be necessary to monitor the patient’s progress.