Mouth Cancer (Chondrosarcoma) in Cats

Oral Chondrosarcoma in Cats

Chondrosarcomas are malignant, cancerous tumors of the cartilage, the connective tissue between bones. These tumors are characteristic for their slow but progressive invasion of the surrounding tissues. They are often mistaken for benign (non-spreading) tumors because of their slow spread and lack of symptoms. They are often found by accident, when they have become large enough to notice, appearing as a lump in the mouth or under the skin of the face, or when they have started to cause pain for the affected animal.

These tumors have a smooth to slightly nodular surface and will often stick to bone, often in the upper jaw, where it is also possible for the tumor to further metastasize (i.e., into the bone). They may also spread to the lungs and sometimes into the lymph nodes. 

This form of cancer is relatively rare in cats.

Symptoms and Types

Chondrosarcomas are commonly located on the upper jaw, which may cause facial deformity or loose teeth. Other symptoms may include:

• Excessive salivation/drooling
• Bad breath (halitosis)
• Weight loss
• Malnutrition
• Difficulty eating, anorexia
• Bleeding from the mouth
• Lymph node swellings in the neck (on occasion)

Causes

• None identified

Diagnosis

You will need to give your veterinarian a thorough history of your cat's health and onset of symptoms. A thorough physical exam in this case will include X-rays of the skull to determine the exact location and severity of the tumor, and to see if it has spread into the bone. Chest X-rays can allow your veterinarian to examine your cat's lungs for further spread of the cancer. 

A large, deep-tissue sample (down to the bone) is required to definitively diagnose the tumor type. If your cat's lymph nodes are enlarged, your veterinarian will also use a fine needle to take fluid and tissue samples from them. The biopsy samples will be sent to a diagnostics laboratory to have the cells analyzed. 

Treatment

Your cat will need to have drastic surgery performed to get as much of the tumor out as possible. Often half of the jaw (most often the upper jaw) is removed. This works well and may even achieve remission if the tumor is removed before it has spread. Your veterinarian may also advise radiation therapy for your cat, but this is highly dependent on the nature and behavior of the tumor and on your cat's overall health. Chemotherapy may be toxic for some animals and should be avoided.

Oral pain medication will need to be administered to the cat to help manage its pain, both before and after surgery.

Living and Management

After surgery, you should expect your cat to feel sore. Your veterinarian will give you pain medication for your cat to help minimize discomfort, and you will need to set up a place in the house where your cat can rest comfortably and quietly, away from other pets, active children, and busy entryways. Setting the cat litter box and food dishes close by will enable your cat to continue to care for itself normally, without exerting itself unduly. Use pain medications with caution and follow all directions carefully; one of the most preventable accidents with pets is overdose of medication.

The location of the surgery will require a special diet. After surgery, you should feed your cat soft foods only, or in some cases foods that are liquefied and fed by tube. Your veterinarian will be able to advise you on what will be best for your cat.

Follow-up visits with your veterinarian will be scheduled for rechecking the progress of healing at the site, as well as for testing for recurrence of the cancer. In some case, the cancer will spread from the lymph nodes to other parts of the body.

In many cases, cats are able to adjust to the changed form of their mouth and face. Patience and affection will be important for helping your cat to transition. Your cat's final prognosis and life expectation will be based on the severity of the tumor's spread into the body.