Stomatitis in Cats: Causes and the FCV Connection

Stomatitis in cats is a severe, often chronic inflammation of the mouth, gums, and tissues at the back of the throat that causes real pain. Its most serious form is chronic feline gingivostomatitis (FCGS), and feline calicivirus (FCV) is one of the leading suspects behind it. Below we explain what the condition is, what drives it, and how it is diagnosed and managed under veterinary care.

A cat resting comfortably at home.

What is stomatitis in cats?

Stomatitis in cats is a widespread, painful inflammation of the soft tissues inside the mouth, including the gums, the inner cheeks, and the arches at the back of the throat. Unlike ordinary dental disease, feline stomatitis involves an intense, exaggerated immune response that leaves the mouth red, swollen, and ulcerated.

When the inflammation becomes long-lasting and extends beyond the gum line, veterinarians call it chronic feline gingivostomatitis (FCGS). This is considered one of the most painful conditions a cat can live with, and it often makes eating, grooming, and even swallowing distressing.

Many caregivers first notice a problem because their cat is drooling, dropping food, or pawing at the mouth. Our companion guide, why a cat's mouth hurts so much with stomatitis, walks through the pain picture in more detail.

What causes stomatitis in cats?

Stomatitis in cats is caused by an over-reactive immune response to material in the mouth, most often plaque and bacteria on the teeth, frequently combined with a viral trigger. In many cats, the immune system responds to normal oral bacteria as if they were a serious threat, producing chronic, self-sustaining inflammation.

Several factors are commonly involved:

• Plaque and dental bacteria that the immune system over-responds to.

• Viral infection, especially feline calicivirus (FCV), which is strongly associated with FCGS.

• Retained tooth roots or existing dental disease that keep the inflammation active.

• Underlying immune stress, including conditions that weaken immune regulation.

Because more than one factor is usually at work, feline stomatitis is best understood as a multi-cause condition rather than a single infection. This is also why treatment often needs more than one approach at the same time.

Why is feline calicivirus a leading suspect in feline stomatitis?

Feline calicivirus is a leading suspect in feline stomatitis because it is detected far more often in cats with chronic feline gingivostomatitis than in healthy cats. FCV is a common respiratory and oral virus, and evidence links it closely with the persistent mouth inflammation seen in FCGS.

FCV commonly causes oral ulcers, drooling, and mouth pain, and in some cats it appears to help drive the ongoing immune over-reaction that defines stomatitis. It is not the only cause, but its frequent presence in affected cats makes it a central part of the investigation.

If you want to understand the virus itself, our overview of feline calicivirus in cats and why it matters explains how it spreads and why it can be so persistent. You can also read about the wider set of feline calicivirus symptoms UK owners report, including drooling, limping, and mouth sores.

How is feline calicivirus different from FIP?

Feline calicivirus and Feline Infectious Peritonitis ("FIP") are two completely different diseases caused by different viruses, and they should not be confused. FCV is a common oral and respiratory virus linked to stomatitis, while FIP is caused by a mutated feline coronavirus and affects the body in very different ways.

They are grouped together here only because CureFIP works across feline antiviral care. FIP has its own signs and its own treatment path, which you can review in our FIP symptoms visual guide for UK owners.

What are the symptoms of chronic feline gingivostomatitis?

The symptoms of chronic feline gingivostomatitis centre on mouth pain and visible inflammation, and they usually get worse over time. Because the condition hurts so much, behaviour changes are often the first clue.

Common signs include:

• Drooling, sometimes with blood-tinged saliva.

• Bad breath (halitosis).

• Dropping food, or crying out while eating.

• Reluctance to eat hard food, or refusing food entirely.

• Pawing at the mouth or face.

• Reduced grooming and a matted, unkempt coat.

• Weight loss and low energy.

• Red, swollen, ulcerated gums and tissues at the back of the mouth.

Sign	Ordinary dental disease	Chronic feline gingivostomatitis
Location	Mainly around individual teeth	Widespread, including the back of the mouth
Pain level	Mild to moderate	Often severe
Eating	May slow down	May refuse food or cry out
Inflammation	Localised	Extensive and ongoing

Our UK owner guide to stomatitis symptoms and causes covers these signs in more depth if you are trying to match what you are seeing at home.

How is stomatitis in cats diagnosed?

Stomatitis in cats is diagnosed by your veterinarian through a physical and oral examination, dental imaging, and tests to identify contributing factors such as feline calicivirus. There is no single home test, so a professional assessment is essential.

A typical diagnostic process includes:

1. A full clinical history, including eating, drooling, and behaviour changes.

2. An oral examination, often under sedation because the mouth is so painful.

3. Dental X-rays to check for retained roots and hidden disease.

4. Testing for underlying infections, which may include FCV and other viruses.

5. Blood work to assess overall health and immune status.

6. In some cases, a tissue biopsy to rule out other conditions.

Because the mouth is usually too sore for a thorough awake exam, much of this is done in one sedated visit. Your veterinarian will use the findings to build a plan suited to your individual cat.

How is stomatitis in cats treated?

Stomatitis in cats is treated with a combination of dental care, pain management, and steps to control the immune and viral drivers of the inflammation. There is no single quick fix, and most cats need a layered plan managed by their veterinarian.

Common components of treatment include:

• Professional dental treatment, which often includes removing severely affected teeth. Many cats improve significantly after extractions because a major source of the immune over-reaction is removed.

• Pain relief and anti-inflammatory support, prescribed and monitored by your veterinarian.

• Management of secondary bacterial infection, where antibiotics address bacteria but do not treat any underlying virus.

• Addressing feline calicivirus, where FCV is identified as a contributing factor.

• Nutritional support, since keeping a painful cat eating is a priority.

Managing the mouth itself is the foundation of care. Antiviral support is considered separately, where a virus such as FCV is confirmed to be part of the picture.

Where does antiviral support fit for FCV-related oral disease?

For oral disease linked to feline calicivirus, EIDD-1931 is the antiviral within the CureFIP range that is positioned for FCV, and the CaliciX line is the FCV-focused EIDD-1931 product. It is intended only for cases where FCV is a confirmed factor, and it does not replace dental treatment or pain relief.

The catalog details for the EIDD-1931 Oral Capsules are below. Any decision to use an antiviral, and any dose, must be confirmed by your veterinarian.

Detail	EIDD-1931 Oral Capsules
Price	€69.00
Dose	1 capsule (15 mg) per 2.5 kg body weight, every 12 hours
Pack	60 capsules per bottle
Standard duration	60 days
Not for	Ocular or neurological cases, and cats not eating or defecating

EIDD-1931 is teratogenic, so it must not be used in pregnant or lactating queens. Because stomatitis often stops a cat from eating comfortably, your veterinarian will also assess whether the cat is well enough for oral medication before starting anything.

Antiviral care is one part of a bigger plan. CureFIP is best known as a GS-441524 antiviral specialist, with more than 100,000 cats supported across our feline antiviral programmes since 2019, and that same commitment to precise, evidence-led information shapes how we talk about FCV and stomatitis.

What is the outlook for cats with feline stomatitis?

The outlook for cats with feline stomatitis is often good when the condition is diagnosed early and managed properly, and many cats become far more comfortable after dental treatment. Some cats need ongoing management, while others improve dramatically once the main triggers are addressed.

Because FCGS can flare and because FCV can persist, this is usually a condition you manage over time rather than resolve in a single visit. Close, ongoing work with your veterinarian gives your cat the best chance of comfortable eating and a good quality of life.

FAQ

Is stomatitis in cats the same as gingivitis?

No. Gingivitis is inflammation limited to the gums, while stomatitis in cats is a more widespread and severe inflammation that extends into the cheeks and the back of the mouth. Chronic feline gingivostomatitis is the most serious form and is considered far more painful than simple gingivitis.

Can feline calicivirus cause stomatitis?

Feline calicivirus is strongly associated with chronic feline gingivostomatitis and is detected more often in affected cats than in healthy ones. It is regarded as a leading contributing factor rather than the single cause, since plaque, bacteria, and immune over-reaction are usually involved too.

Does my cat need teeth removed to treat stomatitis?

Many cats with feline stomatitis improve significantly after dental extractions, because removing severely affected teeth reduces the material driving the immune over-reaction. Whether extractions are needed, and how many, is a decision for your veterinarian based on examination and dental X-rays.

Do antibiotics cure feline stomatitis?

No. Antibiotics address secondary bacterial infection but do not treat any underlying virus or the immune over-reaction that drives feline stomatitis. They are used as one supporting part of a broader plan directed by your veterinarian.

Is stomatitis in cats contagious to other cats?

Stomatitis itself is not directly contagious, but feline calicivirus, which is often linked to it, can spread between cats. If FCV is confirmed, your veterinarian can advise on managing contact and hygiene in multi-cat homes.

If your cat is struggling with a painful mouth, the most important next step is a conversation with your own vet, who can examine your cat and confirm what is driving the inflammation. To learn more about feline antiviral care and the options available, you are always welcome to speak with the CureFIP team and bring those questions to your veterinarian.