Mouth ulcers are painful sores in the lining of a cat’s mouth. They are usually a sign of another problem rather than a condition on their own, so treatment depends on finding the cause. This is general information, not veterinary advice.
What cat mouth ulcers are
An ulcer is an open sore where the surface of the tissue has been lost. In cats it can appear on the gums, tongue, lips, inner cheeks or the roof of the mouth, and the surrounding area is often red and inflamed.
Signs of mouth ulcers in cats
- Drooling, sometimes with blood
- Bad breath
- Eating less, dropping food or crying when eating
- Approaching the food bowl and then backing away
- Pawing at the mouth
- Visible red or raw patches
- Weight loss and a messy coat, because the cat may stop grooming
Common causes
- Dental disease and stomatitis. Severe inflammation of the mouth, including a condition called feline chronic gingivostomatitis, is a recognized cause of painful ulcers.
- Viral infections. Feline calicivirus and feline herpesvirus (the viruses behind the cat cold) are known to cause oral ulcers, especially in kittens and cats from group settings.
- Eosinophilic granuloma complex. Sometimes called “rodent ulcers,” these lesions often affect the lip.
- Kidney disease. Advanced kidney problems can lead to ulcers in the mouth.
- Tumors. Some oral cancers can look like a sore that does not heal.
- Burns and irritants. Chewing electrical cords, caustic substances or some toxic plants can injure the mouth.
- Trauma. Cuts and bites to the cheek or tongue can ulcerate.
Why bad breath and drooling matter
Bad breath, drooling and food avoidance together suggest a painful mouth. Bad breath that lingers, even when your cat yawns, is worth a check. See cat drooling for more on why cats drool and how mouth pain may be involved.
How the vet diagnoses mouth ulcers
Your vet will examine the mouth, though a thorough look often needs sedation or anesthesia because it can be painful. Depending on what they see, they may suggest:
- Bloodwork and urine tests to check for kidney and other illnesses
- Tests for viral infections
- Dental X-rays
- A biopsy of any suspicious tissue
Treatment
Treatment depends on the cause. Options your vet may discuss include:
- Pain relief
- Dental cleaning and extraction of diseased teeth (see what a cat dental procedure involves)
- Medication for infection or inflammation, where appropriate
- Treatment of underlying conditions, such as kidney disease
- Surgery or other care if a growth is found
- Nutritional support when a cat is not eating well (see how to get a cat to eat)
Do not give human pain medication to a cat. Many are toxic to cats.
Is there a fast cure or home treatment?
There is no reliable quick fix at home. Because ulcers have many different causes, treating the wrong cause can delay proper care and let pain continue. The fastest route to relief is to have the cause found and treated. Ask your vet about pain control and what to feed in the meantime.
Caring for your cat at home
- Offer soft, strong-smelling food if your vet agrees.
- Encourage drinking, since sore mouths can reduce intake.
- Keep the environment calm.
- Watch weight and appetite closely, and report changes.
- Follow your vet’s instructions for medication and recheck visits.
When it is urgent
Contact your vet quickly if your cat stops eating or drinking, because cats that go without food can develop serious problems. Also call promptly for heavy bleeding, swelling, breathing trouble or lethargy. A hard lump on the face may be an abscess; see cat abscess on cheek.
FAQ
How do I treat my cat’s mouth infection?
Have a vet identify the cause. Treatment may include dental work, medication and pain relief.
What is the silent killer of cats?
There is no single answer. Kidney disease is often called a silent illness because signs can be subtle, and it can cause mouth ulcers. Regular vet checks help catch it.
Can I tell ulcers from normal gums?
Compare with what is normal. See normal cat gums and healthy cat tongue color.