Stomatitis in Cats: Signs, Causes, and Treatment
From PawPedia, an encyclopedia of life with animals
Contents
| Also called | Feline chronic gingivostomatitis; FCGS |
|---|---|
| Cause | Exact cause unknown; the leading theory is that the immune system overreacts to plaque on the teeth |
| How it spreads | Stomatitis itself is thought to be driven by the cat's immune reaction; calicivirus and FIV, linked with it, spread between cats |
| First signs | Signs often build slowly; many owners first notice a change in how the cat eats |
| Common signs | Bad breath, drooling, crying out when eating or yawning, dropping food, eating less, weight loss, and a messy coat |
| Diagnosis | Mainly what the vet sees in the mouth, especially at the back, often under sedation or anesthesia |
| Treatment | A vet removes teeth, which works best long term in most cats, and may prescribe pain relief; never give human pain medicine |
| Outlook | With early extraction, 60 to 80 percent of cats improve greatly or appear cured |
| Prevention | No sure way to prevent it; vaccination, neutering, and testing new cats for FIV and FeLV lower the risk from linked infections |
| Risk to people | Calicivirus and FIV, two viruses linked with it, do not infect people or dogs |
| Emergency if | Not eating or drinking, weakness or dehydration, heavy bleeding from the mouth, a swollen face, or sudden mouth ulcers or burns |
Stomatitis means inflammation of the soft tissues inside the mouth. In cats, the word usually refers to a long-term condition called feline chronic gingivostomatitis, or FCGS. The gums turn bright red and sore, and the inflammation spreads to the cheeks, the tongue and the back of the mouth. It is very painful. Many affected cats are hungry and want to eat, but they stop because chewing hurts.
Stomatitis is more than ordinary gingivitis. Gingivitis stays on the gum line next to the teeth. With stomatitis, the inflammation reaches the back of the mouth, usually on both sides of the base of the tongue. Vets look at this area to tell the two conditions apart.
Signs to watch for
The signs often build slowly. Many owners first notice a change in how the cat eats, before they ever see the mouth itself.
- Bad breath
- Drooling or a wet chin
- Crying out or flinching when yawning or eating
- Walking up to the food bowl, then backing away without eating
- Dropping food or having trouble swallowing
- Eating less and losing weight
- A messy or matted coat, because grooming hurts
- Swollen glands under the jaw
If you gently lift the lip, the gums may look bright red, swollen or raw. Many cats with stomatitis will not allow this, and forcing the mouth open can hurt them. Your veterinarian can examine the mouth safely.
When it is an emergency
Stomatitis is usually a long-term problem, but some situations need a vet the same day. Call your clinic if your cat has stopped eating or drinking, seems weak or dehydrated, bleeds heavily from the mouth, or has a swollen face. Cats that go without food can develop a serious liver condition called hepatic lipidosis, and overweight cats are at higher risk. A cat that refuses all food should be seen soon.
Sudden mouth ulcers or burns are also urgent. They can happen after a cat bites an electric cord or licks a household chemical. Kidney failure can cause mouth ulcers too, and it needs prompt care of its own.
What causes it
The exact cause is still unknown. The leading theory is that the immune system overreacts to plaque, the film of bacteria that builds up on the teeth. The body responds with far more inflammation than plaque would normally cause, and the tissues of the mouth are damaged in the process.
Several infections are linked with the condition. Feline calicivirus, a common cause of upper respiratory infections in cats, is found much more often in cats with stomatitis than in healthy cats. In some studies, almost every affected cat was a long-term carrier. The feline immunodeficiency virus (FIV) is also linked, and gum and mouth inflammation is common in FIV-positive cats. Feline leukemia virus (FeLV), feline herpesvirus and Bartonella bacteria have been found in some cases as well. None of these explains every case, and many cats carry calicivirus without ever developing stomatitis.
A new calicivirus infection can also cause painful ulcers on the tongue and gums, usually for a short time. This is a different problem from chronic stomatitis, and your veterinarian will consider it along with the other causes above.
Rescued and newly adopted cats
Calicivirus spreads easily wherever many cats live close together, such as shelters, catteries and street colonies. Infected cats shed the virus in saliva and nose discharge, most for at least a month and a few for years. The virus can stay infectious on dry surfaces for up to a month. FIV spreads mainly through deep bite wounds, so it is more common in cats that roam and fight, especially unneutered males. Many rescued cats come from these backgrounds.
At Paw Squadron, the first stops after every rescue are the vet and a bath. Every animal gets a checkup, treatment, vaccinations and a microchip before adoption. When you adopt a cat, ask what the vet noticed in the mouth and whether the cat has been tested for FIV and FeLV. Plan a visit to your own veterinarian in the first weeks, and ask them to check the gums and the back of the mouth.
How vets diagnose it
The diagnosis rests mainly on what the vet sees in the mouth, especially the inflammation at the back. The mouth is often too painful for a full look while the cat is awake, so sedation or anesthesia is common.
Blood and urine tests check for kidney disease and other illness that can affect the mouth. Tests for FIV and FeLV are usually part of the workup, and some vets also test for calicivirus. Dental X-rays show damage to tooth roots and bone that cannot be seen from outside. If the tissue looks unusual, or only one side of the mouth is affected, the vet may take a small tissue sample, called a biopsy, to rule out mouth cancer, which can look similar.
How it is treated
Treatment aims to control pain and to remove what the immune system is reacting to. Removing teeth gives the best long-term results in most cats. Depending on where the inflammation is, the vet removes either all the teeth behind the canines or every tooth. Dental X-rays are then taken to confirm that no root pieces remain, since leftover roots can keep the mouth inflamed.
Many owners find this hard to accept at first. Most cats eat well without teeth once the mouth has healed. When extraction is done early in the disease, 60 to 80 percent of cats improve greatly or appear cured. Some cats improve slowly over weeks or months, and some still need medicine afterward to keep the inflammation under control.
Medicine alone can help for a while. Your veterinarian may prescribe pain relief, anti-inflammatory drugs, antibiotics, and antiseptic rinses or gels. Steroids can ease the inflammation, but they usually work less well with repeated use. Cats that stay on medicine for a long time before surgery tend to respond less well to extraction, so it is worth discussing surgery with your vet early. For cats that do not respond fully, vets sometimes add treatments that calm the immune response. Very sick cats that refuse food may need a stay in the clinic, with fluids or a temporary feeding tube.
Human pain medicines can be very dangerous for cats. Please give only what your veterinarian prescribes.
Soft, wet food is easier to eat while the mouth is sore or healing. Medicine and rinses work best when given as your vet explains. Recheck visits are usually recommended, since some cats need their plan adjusted over several months. If your cat still has some teeth, daily tooth brushing can help keep plaque down once the mouth is no longer painful. Ask your vet when it is safe to start.
Risk to other pets and people
Stomatitis is thought to be driven by the cat's own immune reaction. Some of the infections linked with it, however, are contagious between cats. Calicivirus spreads through saliva and nose discharge, and on shared bowls, bedding and hands. FIV spreads mainly through bites. Neither virus infects people or dogs. If you have other cats, it helps to wash bowls and bedding often. Ask your vet which disinfectant works against calicivirus, since it survives many common cleaners.
How to lower the risk
There is no sure way to prevent stomatitis, since the cause is not fully understood. These steps can lower the risk from the infections linked with it.
- Keeping vaccinations up to date. The core cat vaccine covers calicivirus. It usually protects against illness, although it does not always stop infection.
- Asking your vet about FIV and FeLV testing before a new cat meets your other cats, and introducing new cats slowly.
- Neutering, and keeping cats indoors or in a secure outdoor area, which cuts down on fights and bites.
- Keeping cats in small, stable groups where possible.
- Having a yearly checkup that includes a look in the mouth, and brushing your cat's teeth if your cat accepts it.
Stomatitis can be a long-term condition, but many cats become comfortable again with the right plan. If you have questions about the health of a cat you would like to adopt, send an adoption inquiry. You can find more cat care guides in PawPedia.
See also
From our rescues
This article is general information, not veterinary advice. Always consult a veterinarian about your animal’s health. Some pictures in PawPedia may be AI-generated.
This page was last updated on October 23, 2026.