Gingivitis in cats shows up as a thin red line along the gumline where the gums meet the teeth. In a healthy cat, the gums are pale pink and firm. When gingivitis develops, that clean pink color shifts to red, and the tissue looks puffy or swollen. Roughly 80 to 85 percent of cats over age two have some form of dental disease, so this is one of the most common problems you’ll spot if you lift your cat’s lip.
What Healthy vs. Inflamed Gums Look Like
Healthy cat gums are a consistent light pink, similar to the inside of your own lip. They sit snugly against each tooth with no gaps or puffiness. When gingivitis sets in, the gum tissue right at the base of the teeth turns red and begins to swell. In early stages, this may look like nothing more than a slightly darker pink border. As it progresses, the redness deepens to a bright or angry red, and the gums appear visibly thickened.
The inflammation usually starts around one or two teeth, then spreads. By the time most cat owners notice something is off, the redness has often moved beyond the area around a single tooth and may involve larger stretches of the gumline or tissue toward the back of the mouth.
Mild, Moderate, and Severe Stages
Veterinarians grade feline gingivitis on a three-point scale:
- Mild (Grade 1): Slight swelling and a faint increase in redness along the gumline. Easy to miss if you aren’t looking closely.
- Moderate (Grade 2): Noticeable swelling and redness. The gums bleed when probed or touched firmly.
- Severe (Grade 3): Dramatic swelling, deep red or purplish gums, and spontaneous bleeding without any contact.
At Grade 1, you might only see the problem in good lighting with your cat’s lip pulled back. By Grade 3, you may notice blood on your cat’s toys, food bowl, or in their saliva without ever looking inside their mouth.
Behavioral Signs You Might Notice First
Cats are notoriously good at hiding pain, so the visual signs inside the mouth often go unnoticed. Behavioral changes tend to be the first red flag. A cat with gingivitis may hesitate before eating, chew on one side, tilt their head at an odd angle while eating, or suddenly prefer soft food over kibble. Some cats stop eating altogether when the pain becomes severe enough.
Drooling is another common sign, especially if you notice saliva that’s tinged pink or red with blood. Bad breath that smells sour or rotten is one of the earliest and most reliable clues. Some cats will paw at their face or become unusually irritable when their mouth is touched.
Gingivitis vs. Stomatitis
Gingivitis affects the gum tissue directly surrounding the teeth. Stomatitis, a more severe condition, involves inflammation that extends beyond the gums into the tissue at the back of the mouth, beneath the tongue, or along the inner cheeks. The key visual difference: gingivitis stays close to the teeth, while stomatitis creates angry, ulcerated tissue in areas far from any tooth.
In stomatitis, the immune system overreacts to plaque and causes widespread inflammation. The tissue becomes swollen, ulcerated, and bleeds easily. Cats with stomatitis often drool heavily, sometimes with visible blood in the saliva. Gingivitis that responds to a professional dental cleaning is less likely to progress to full stomatitis, but cases where the back of the mouth is already inflamed typically need more aggressive treatment, sometimes including extraction of most or all teeth.
What Causes It
Plaque buildup is the primary trigger. Bacteria naturally colonize the surface of a cat’s teeth, forming a sticky film. When that plaque isn’t disrupted, it hardens into tartar and triggers an immune response in the surrounding gum tissue. The specific bacteria involved overlap with species found in human gum disease, though no single bacterial species has been identified as the definitive cause in cats.
Certain viral infections raise a cat’s risk. Cats with feline immunodeficiency virus (FIV) show higher levels of bacteria associated with oral disease and a disrupted oral microbiome compared to uninfected cats. Feline leukemia virus (FeLV) has also been linked to higher rates of severe oral inflammation. That said, the connection between these viruses and gingivitis appears to be more about the weakened immune system than any direct effect on the mouth’s bacterial balance.
What Happens at the Vet
Your vet will examine your cat’s mouth visually, but a thorough assessment requires anesthesia. Under sedation, the vet can probe the gums around each tooth, take dental X-rays to check for bone loss beneath the gumline, and clean below the gumline where plaque and tartar hide. This matters because gingivitis that has progressed to periodontitis involves damage to the bone and ligaments holding teeth in place, which isn’t visible just by looking at the gums.
If the gingivitis is caught early and hasn’t damaged deeper structures, a professional cleaning can reverse it. The gums heal and return to their normal pink color within a few weeks. Once bone loss has occurred, the damage is permanent, and treatment shifts to managing the disease and extracting teeth that can no longer be saved.
Preventing and Slowing Gingivitis at Home
Daily tooth brushing is the most effective way to disrupt plaque before it hardens. Use a small, soft-bristled brush or a finger brush designed for cats, along with toothpaste formulated for pets (human toothpaste contains ingredients that are toxic to cats). Even brushing a few times a week makes a measurable difference compared to no brushing at all.
If your cat won’t tolerate a brush, alternatives exist. The Veterinary Oral Health Council (VOHC) maintains a list of products that meet their standards for reducing plaque or tartar in cats. Accepted options include water additives, dental wipes, topical gels, oral sprays, and specific dental treats. Products with the VOHC seal for plaque control help prevent the bacterial film that triggers gingivitis, while those accepted for tartar control slow the hardening of plaque into calculus. Some products carry both claims.
No home care method replaces professional cleanings, but consistent daily or near-daily care extends the time between cleanings and can keep mild gingivitis from progressing. If you’re already seeing a red line along your cat’s gums, that’s a sign plaque has been building for a while, and a professional cleaning is the fastest way to reset the clock before home care can take over.