What Is Oral Squamous Cell Carcinoma?
Oral squamous cell carcinoma (SCC) is a cancer of the cells lining the mouth and the most common oral tumor in cats, making up well over half of feline mouth cancers. It usually affects older cats, often around 10 to 12 years of age, and most often grows under the tongue, along the gums and jawbone, or in the tonsils. It is locally aggressive, invading deep into soft tissue and bone, although spread to distant organs is less common than with many other cancers.
The exact cause is not known. Studies have linked a higher risk to flea collars, diets heavy in canned food (especially tuna), and exposure to household tobacco smoke, but none of these has been proven to cause it. Oral SCC in cats behaves very differently from oral melanoma in dogs, the most common malignant mouth tumor in dogs.
Why it matters
Oral SCC often looks like an ordinary sore, a bad tooth, or gum inflammation at first. Biopsying any mouth lesion that does not heal quickly gives the best chance of finding it while it is still small.
Signs Owners Notice
- Drooling, sometimes with blood, or a wet or matted chin
- Strong bad breath
- Eating less, chewing on one side, dropping food, or not eating at all
- Weight loss and a scruffy coat from reduced grooming
- Swelling of the jaw or face, loose teeth, or pawing at the mouth
- A raised, red, or ulcerated area under the tongue or on the gums
Diagnosis
Many early cases are first treated as dental disease or stomatitis, because the signs overlap. A deep tissue biopsy under anesthesia is the only way to confirm SCC. Your vet will usually also recommend dental X-rays or a CT scan to see whether the jawbone is involved, chest X-rays, and sampling of the lymph nodes under the jaw. Other mouth tumors, such as lymphoma or fibrosarcoma, are ruled out at the same time.
Treatment and Outlook
- Surgery: removing the tumor with part of the jaw offers the best outcome for small tumors near the front of the lower jaw. Tumors under the tongue or at the back of the mouth are rarely removable.
- Radiation therapy: used to shrink tumors and ease pain, sometimes combined with surgery or chemotherapy.
- Anti-inflammatory and pain medicines: prescribed for comfort and may slow tumor growth slightly in some cats.
- Feeding tube: a small tube placed in the neck lets cats get food, water, and medicine when eating becomes painful.
- Clinical trials: veterinary schools sometimes offer newer treatments for feline oral SCC.
The outlook for most cats is poor because the cancer is often advanced at diagnosis; untreated cats commonly survive only a few months. Cats with small tumors that can be removed completely can do much better, sometimes living a year or longer. Comfort and quality of life should guide decisions, and a veterinary oncologist can help weigh the options and costs.
Practical Tips for US Pet Owners
- Lift your cat’s lips and look under the tongue during brushing or petting, especially after age 10.
- Ask for a biopsy if a mouth sore has not healed within two weeks of treatment.
- Keep cats away from tobacco smoke and use vet-recommended flea products instead of old-style flea collars.
- Find a nearby practice through veterinary clinic listings.
When to see a vet
Book a visit within a few days for drooling, bloody saliva, a mouth lump, or a senior cat that suddenly struggles to eat.
Key Takeaways
- Oral SCC is the most common mouth cancer in cats, mostly in seniors.
- It often mimics dental disease, so non-healing mouth lesions need a biopsy.
- Early surgery offers the best chance; pain control and nutrition support are central at every stage.
FAQ
Can a dental cleaning cure my cat’s mouth sore?
Not if the sore is cancer. If a lesion remains after dental treatment, a biopsy is the next step.
Is oral SCC painful for cats?
Yes, it is usually painful, especially once it reaches the bone. Your vet can prescribe medicines to keep your cat comfortable.
Can cats eat after jaw surgery?
Many cats adapt and eat on their own after recovery, though some need a feeding tube for a few weeks.