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Squamous cell carcinoma of cats
Squamous cell carcinoma is a cancer of cells of the skin and mucous membranes. In cats, it takes on two very different faces. The cutaneous form affects areas with little hair and little pigment exposed to the sun: edges of the ears, nose,...
What is it?
Squamous cell carcinoma is a cancer of cells of the skin and mucous membranes. In cats, it takes on two very different faces.
The cutaneous form affects areas with little hair and little pigment exposed to the sun: edges of the ears, nose, eyelids. It is mainly seen in white or white-faced cats and begins with simple scabs that do not heal.
The oral form develops under the tongue or in the jaw. It is more discreet at first, more serious, and manifests itself in difficulty eating.
Commonly observed signs
These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.
Related signs — each one links to its page:
Cutaneous form: crust, redness or small sore on the edge of an ear, on the nose or on an eyelid, which seems to heal then returns.
The lesion spreads slowly, bleeds easily, deepens into an ulcer and nibbles at the edge of the ear, which appears eaten away.
It is often painful: the cat scratches its ear, shakes its head or avoids having its nose touched.
Oral form: marked bad breath, copious salivation sometimes tinged with blood, difficulty chewing and swallowing.
The cat drops its kibble, eats on one side, then stops eating and loses weight.
A tooth that moves for no reason, swelling of the jaw or facial deformity may be the first signs.
Grooming deteriorates and the coat becomes dull, because the cat can no longer lick itself properly.
When to consult without delay
This list does not replace veterinary advice. It gathers situations that justify a prompt consultation.
Causes and risk factors
Repeated exposure to ultraviolet radiation from the sun damages skin cells, which eventually change. This is the well-established cause of the cutaneous form.
Light, poorly pigmented skin with little hair does not offer any protection: this is why white cats are the most affected.
The lesion often goes through a precancerous stage, marked by redness and recurrent crusts, before becoming a real cancer.
For the oral form, the exact cause is not established. Chronic inflammation of the mouth, exposure to tobacco smoke in the home and certain grooming habits have been cited as contributing factors.
White coat or white face, depigmented ears and nose.
Outdoor life or habit of sleeping in the sun, behind glass or on a windowsill.
Very sunny region and altitude, which increase exposure to ultraviolet rays.
Age: the cutaneous form mainly affects adult to elderly cats, after years of cumulative exposure.
Chronic inflammation of the mouth and poor dental condition for the oral form.
Smoking in the home.
Diagnosis and care
Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.
Any crust on the edge of the ear or nose that does not heal within a few weeks should be shown: at this early stage, treatment is simple and often curative.
The veterinarian examines the lesion, nearby lymph nodes and the mouth as a whole.
The diagnosis requires a sample of tissue analyzed in the laboratory: the visual appearance is not enough, other diseases cause similar lesions.
For the oral form, the examination is carried out under anesthesia, with dental x-rays or a scanner to assess the damage to the jaw bone.
The lymph nodes in the region are punctured to look for extension.
Chest x-rays complete the assessment.
Treatment
Cutaneous form caught early: large surgical removal is the treatment of choice, with very good results. On the ear, this means removing the pinna down to healthy tissue — the aesthetic result surprises owners, but the cat copes very well with it and does not suffer from it.
On the nose or eyelids, the surgery is more delicate; other local techniques exist, such as cryotherapy or radiotherapy, depending on the equipment available.
Oral form: it is difficult to treat because the tumor quickly invades the jaw bone and is often discovered late. Large surgery is sometimes possible on well-localized lesions of the jaw.
Radiotherapy and chemotherapy are used in certain situations, rather to slow the disease than to cure it.
In all cases, pain control is a priority, as is maintaining nutrition: fitting a feeding tube allows cats to remain comfortable and regain weight when eating becomes too difficult.
When the disease is too advanced, well-conducted palliative care, then the choice of euthanasia at the right time, are among the decisions to be made with the veterinarian.
Treatment depends on the cause and the animal's condition: it must be determined by a veterinarian. No self-medication.
Prevention
Limit white cats' exposure to the sun: keep them indoors during the hottest hours, between mid-morning and late afternoon.
Pay attention to sunny places behind glass, very popular with cats.
Veterinary sunscreens, suitable and non-toxic if licked, can be applied to the nose and the edges of the ears; never use a human product without veterinary advice, as certain components are dangerous for cats.
Regularly examine the ears and nose of white cats, and promptly show any returning crust.
Maintain oral health and have your mouth checked at each annual visit.
Do not smoke inside the accommodation.
Possible complications
Progressive destruction of the edge of the ear, nose or eyelid if the lesion is not treated.
Infection and bleeding from ulcerated areas.
Eye damage for eyelid lesions.
Invasion of the jaw bone in the oral form, with significant pain and possible fractures.
Malnutrition and severe weight loss when the cat can no longer eat.
Appearance of new lesions elsewhere on areas exposed to the sun, in a cat already operated on.
When to see a veterinarian
Your cat has a scab on the edge of the ear or on the nose that does not heal within a few weeks.
A small wound always comes back to the same place, bleeds or gets bigger.
His breath becomes very bad, he drools, or his saliva is tinged with blood.
He eats on one side, drops his kibble or refuses to eat.
His jaw or face becomes deformed, a tooth moves without trauma.
He neglects himself, no longer washes and loses weight.
Prognosis
The cutaneous form taken at an early stage is treated very well: extensive surgery on an early lesion of the ear pinna is often permanent.
The more extensive the lesion is or located in an area that is difficult to operate on widely – nose, eyelids – the more the risk of regrowth increases.
The oral form has a much worse prognosis: it is aggressive, invades the bone and is often discovered late. The comfort of the animal then becomes the main objective.
A white cat already treated for a lesion must be monitored throughout its life: other exposed areas may be affected in turn.
Frequently asked questions
My white cat has had a scab on his ear for months: is it serious?
This must be shown to a veterinarian. A scab that keeps coming back in the same place on a white ear is the very first possible stage of this cancer, and this is precisely when treatment is most effective.
Will my cat lose its ears?
If the lesion is on the pinna, surgery consists of removing the affected part with a safety margin. The appearance changes, but the hearing is preserved, the cat no longer suffers and it adapts without difficulty.
Can I put my sunscreen on his nose?
No. Human creams contain components that can be toxic to the cat, which licks it. Ask your veterinarian for a product adapted to the species.
Is an apartment cat safe?
Less exposed, but not completely: cats like to sleep in the sun behind glass. In a white cat, still watch the ears and nose.
References
AAFP — American Association of Feline Practitioners
Content reviewed by the TunisieVet editorial team · Updated 09 August 2026
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