Cat Stomatitis: Signs of Painful Mouth Disease and What to Do

If your cat has suddenly stopped eating, is drooling, or seems reluctant to groom, feline stomatitis might be the cause. In 2026, veterinary dentists consider stomatitis one of the most painful conditions a cat can experience — and one of the most commonly underdiagnosed because cats are experts at hiding pain.

What Is Feline Stomatitis?

Feline stomatitis (also called feline chronic gingivostomatitis, or FCGS) is severe, widespread inflammation of the mouth, gums, and soft tissues of the oral cavity. Unlike ordinary gingivitis, which affects just the gums near the teeth, stomatitis typically extends deep into the throat (the caudal mucosa), causing ulceration and intense pain with every swallow.

According to VCA Animal Hospitals, the exact cause is not fully understood, but it's believed to involve an abnormal immune response to bacterial plaque, viral antigens (especially from feline calicivirus and herpesvirus), or both. The immune system essentially attacks the cat's own oral tissues.

Signs of Cat Stomatitis

Cats rarely cry out when their mouth hurts — instead, you'll notice behavioral changes:

• Drooling, often excessive or blood-tinged
• Difficulty eating — pawing at the face, dropping food, preferring soft foods, or refusing to eat entirely
• Weight loss due to pain while chewing
• Bad breath (halitosis) that is unusually severe
• Reluctance to be touched near the face or head
• Decreased grooming — even a small movement of the mouth hurts
• Chattering or grinding jaw motions
• Red, angry-looking tissue visible at the back of the mouth

A cat with severe stomatitis may stop eating entirely. Left untreated, this leads to rapid weight loss in cats and serious nutritional deficiencies.

When to Worry — Emergency Signs

Get veterinary attention promptly if your cat:

• Has completely stopped eating for more than 24 hours
• Is losing significant weight
• Has bright red or ulcerated tissue visible in the mouth
• Is drooling blood or thick, foul-smelling saliva
• Shows signs of pain when yawning or opening the mouth

Diagnosis and Treatment

Stomatitis is diagnosed by oral examination, often under anesthesia for a full assessment. Your vet may recommend:

• Dental X-rays to assess tooth root involvement
• Full-mouth tooth extraction — counterintuitive but often the most effective treatment. Removing all or most teeth eliminates the plaque that drives the immune response. Studies show approximately 60–80% of cats improve significantly after extraction.
• Medical management — steroids, immunosuppressants, and pain relief can help, but usually provide temporary relief rather than long-term resolution
• Laser therapy — used in some specialty practices to reduce inflammation

How Voyage Can Help

Wondering if your cat's bad breath and food avoidance could be stomatitis? Voyage AI Vet can help you assess symptoms and decide when to book a vet appointment — for $4.99/month. For cats that have stopped eating, don't delay.

What To Do at Home

There is limited effective home treatment for stomatitis — this condition requires professional veterinary care. While waiting for your vet appointment:

• Offer soft or liquid foods (wet food, warmed broth) to encourage eating
• Avoid dry food, hard treats, or anything requiring extensive chewing
• Do not attempt to clean your cat's teeth if they are clearly in pain

Frequently Asked Questions

Q: Can stomatitis be cured in cats? A: Full remission is possible, especially after full-mouth extraction, but some cats require ongoing management. About 20% of cats don't fully respond even after extraction.

Q: Is stomatitis contagious to other cats? A: Stomatitis itself is not contagious, but the underlying viral triggers (calicivirus, herpesvirus) can spread between cats. Keep affected cats separated and ensure all cats are up to date on vaccinations.

Q: My cat has bad breath and is grooming less — could this be stomatitis? A: These are classic early signs. A vet examination is needed to distinguish stomatitis from dental disease, tooth resorption, or other causes. Read more about cat dental disease for comparison.

Q: How much does stomatitis treatment cost? A: Full-mouth extraction typically costs $500–$2,000+ depending on your location and clinic. While significant, it often provides more lasting relief than repeated medical management.

Q: What age do cats typically develop stomatitis? A: Stomatitis can occur at any age, including young adult cats, but it's often first diagnosed in middle-aged cats (3–8 years). Certain breeds like Siamese and Abyssinians may have higher prevalence.

This article is for informational purposes only and is not a substitute for professional veterinary advice.