Cancer: Squamous Cell Carcinoma in Cats

cat by the window

Dr. Phil Zeltzman is a traveling, board-certified surgeon in Allentown, PA. His website is He is the co-author of “Walk a Hound, Lose a Pound” (

Kelly Serfas, a Certified Veterinary Technician in Bethlehem, PA, contributed to this article.

Squamous cell carcinoma is a type of cancer found in various locations in cats, usually older.

Squamous cell carcinoma in the skin
It can develop in the skin, mostly in white cats and thinned-haired cats, especially those who enjoy sun bathing behind a window. Two areas of predilection seem to be the nose and the ears. When it happens on the ear, the cancer typically starts with blackish crusts. It doesn’t look like much initially; then it slowly progresses along the ear and gives it a (black) shriveled-up or cauliflower appearance. This type of squamous cell carcinoma may be somewhat similar to skin cancer in people exposed to sun.

Squamous cell carcinoma in the mouth
Squamous cell carcinoma can also develop inside the mouth of cats. About 10% of all tumors found in cats are oral squamous cell carcinoma. Unfortunately, this can be difficult to diagnose, as most cats don't like anyone to open their mouths! It is also challenging because some cats may “only” have bad breath and drooling, which can all be blamed (by mistake) on bad teeth. Because of difficulty eating, these cats slowly lose weight. Some cats may not exhibit any of these signs until the cancer has progressed significantly. Probably the most obvious location for squamous cell carcinoma of the jaw is when it occurs in the chin. In such cases, the chin becomes larger and firmer over time.

Squamous cell carcinoma treatment
Squamous cell carcinoma is a rapidly growing cancer, and 90% of cats diagnosed with the oral form die within one year. If the cancer has not spread to the lymph nodes or lungs, which fortunately is often the case, surgery can be performed to remove the tumor. Some family veterinarians, and more commonly surgeons, would tackle such an invasive operation, as it requires a good understanding of cancer surgery and it may require special equipment. Chemotherapy and radiation are rarely beneficial with this type of cancer, and surgical removal is the best course of treatment.

Early diagnosis and treatments are the key for a good outcome. Surgery must be aggressive because the cancer is growing aggressively. If squamous cell carcinoma is found in the jaw, part of the jaw must be removed (partial maxillectomy or partial mandibulectomy). If it is found on the ear, the ear flap must be removed (pinnectomy or otectomy). Occasionally both ears are affected at the same time! If it is found on the tip of the nose, the nose must be removed ("nose-ectomy"). Surprisingly, cats are able to function quite well in spite of their new appearance. They can eat even after part of the jaw has been removed, and they can breathe after a “nosectomy.” Certainly, they don’t care about the way they look. They just want to be comfortable. As I always say: please never tell your pets they have cancer!

Squamous cell carcinoma prevention
Prevention is difficult at best. It includes avoiding prolonged exposure to direct sunlight, especially for white or light-colored cats.

There is however one way to significantly decrease the risk of squamous cell carcinoma of the mouth. Several studies, including one discussed on and another found on the National Center for Biotechnology Information’s website, suggest that there is a connection between secondhand smoke and squamous cell carcinoma in the mouth of cats. Cats exposed to secondhand smoking for more than 5 years and cats living with more than one smoker are more likely to be affected by this cancer. How do they get it? Because cats groom so much, they lick carcinogens that land on their fur.

If you ever notice changes in your cat’s skin, ears, nose or jaws, please don’t procrastinate; make an appointment with your family veterinarian.

Questions to ask your veterinarian

  • What is this strange swelling or change I noticed on my cat’s skin or ear, or inside the mouth?
  • Should I discuss my options with a board-certified oncologist (cancer specialist)?
  • Should I get a referral to a board-certified surgeon?

If you have any questions or concerns, you should always visit or call your veterinarian -- they are your best resource to ensure the health and well-being of your pets.

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