Also referred to as malignant neoplasms or malignant tumours, cancer is the uncontrolled division of cells that normally should be restricted in their growth. Tumours are split into two categories, malignant (cancerous) or benign. Benign tumours grow slowly, are surrounded by a capsule and do not invade neighbouring tissue or spread to other areas.
Ten percent of all cancers in cats are oral cancer with squamous cell carcinomas (SCC) being the most frequent type of oral cancer. This type of cancer accounts for 60-70% of all oral cancers in cats. The next most frequent are fibrosarcomas, other cancers include lymphoma and malignant melanoma.
This article will refer to SCC as it is the most common type of oral cancer in cats.
SCC is a particularly aggressive cancer, rapidly growing and invading nearby tissues and bone. It is rare for SCC to metastasize to other areas of the body. The disease is usually found in older cats, with the average onset of disease being 12 years. Flea collars, exposure to cigarette smoke and regularly feeding canned cat food, especially tuna flavour are all factors.
As this type of cancer is so quick to invade surrounding areas, early diagnosis is extremely important for this type of cancer.
What are the symptoms of oral cancer in cats?
Symptoms of oral cancer in cats typically include:
- Red, ulcerated swelling in the mouth appearing on the gums, tongue or underneath the tongue.
- Difficulty eating.
- Painful mouth and/or face.
- Bleeding in the mouth.
- Bad breath.
- Swollen face.
- Loose teeth.
- Enlarged lymph nodes under the jaw.
- Grooming less.
- Weight loss due to loss of appetite.
How is oral cancer diagnosed?
Your veterinarian will perform a complete physical examination of your cat, carefully checking the oral cavity for lumps and loose teeth (which can be indicative of bone loss) as well as checking local lymph nodes for signs of enlargement. He will obtain a medical history from you, including how long you have noticed the growth and other symptoms. Tests will need to be performed to confirm a diagnosis. These will include:
- Biochemical profile, complete blood count, and urinalysis to evaluate the overall health of your cat.
- Biopsy of the growth which will be sent to a laboratory for evaluation. This is performed under general anesthesia.
- X-rays will also be taken while the cat is under anesthesia to determine the extent of bone involvement. Additional chest x-rays may also be recommended to check for signs of metastasis in the lungs.
How is oral cancer treated?
Most cancers are referred to specialist veterinary centres. The outcome for cats with oral cancer is poor, with few surviving past the 1-year mark. In many cases, surgery is not practical, even when surgical removal occurs, the recurrence rate is very high.
Treatment can be difficult due to cancer quickly invading surrounding tissues.
- If the tumour is found early enough and is in the front portion of the mandible (lower jaw) surgery (mandibulectomy) may be performed.
- Cryosurgery (freezing) may be performed on small tumours.
- Radiotherapy may be recommended after surgery.
- If the tumour is too large, or not in a part of the mouth which can be surgically treated, radiotherapy and/or chemotherapy may be used to slow down the growth of the tumour.
- Non-steroidal anti-inflammatory drugs (NSAIDS) such as piroxicam have been found to slow down the growth of the tumours.
- Antibiotics may also be prescribed to treat bacterial infections which are common with oral cancers.