Periodontal disease is a progressive infection of the gums and the structures that hold your cat’s teeth in place. It starts with bacteria building up along the gumline and, left unchecked, destroys bone and tissue until teeth loosen and fall out. The risk climbs steeply with age: roughly 13% of cats between 3 and 6 years old are affected, rising to about 27% of cats 15 and older, based on a large UK veterinary study of over 18,000 cats.
How Periodontal Disease Develops
The process begins with plaque, a sticky film of bacteria that forms on your cat’s teeth within hours of eating. If plaque isn’t disrupted, it hardens into tarite (calcite) within days and creates a rough surface where even more bacteria thrive. A healthy cat’s gum pocket, the tiny space between the tooth and gum, measures less than half a millimeter deep. When plaque accumulates undisturbed, gum inflammation can set in within two to three weeks.
As bacteria multiply beneath the gumline, the body’s immune response actually contributes to the damage. Inflammatory chemicals meant to fight infection also break down the connective tissue and bone anchoring the teeth. The bacterial population shifts too. Healthy cat mouths are dominated by relatively harmless species, but diseased gums harbor a different community, including corkscrew-shaped bacteria and other species associated with tissue destruction.
The Four Stages
Veterinarians grade periodontal disease on a scale from Stage 1 to Stage 4, based on how much attachment between tooth and bone has been lost.
Stage 1: Gingivitis. The gums are red, swollen, and bleed easily when touched, but no bone or attachment loss has occurred. This is the only fully reversible stage. The gum edges, which should look thin and crisp, appear puffy and rounded.
Stage 2: Early periodontitis. The tissue connecting the tooth root to the surrounding bone starts to break down, with less than 25% of attachment lost. Gums may begin to recede, and shallow pockets form around affected teeth. On multi-rooted teeth, the space where roots divide may become exposed.
Stage 3: Moderate periodontitis. Between 25% and 50% of the tooth’s attachment is gone. Bone loss becomes visible on dental X-rays, and pockets deepen further.
Stage 4: Severe periodontitis. More than half the attachment has been destroyed. Teeth become visibly loose and may fall out on their own. Heavy tartar buildup and pronounced gum recession are common at this point.
Signs You Might Notice at Home
Cats are exceptionally good at hiding pain, which is why periodontal disease often progresses silently. Most cats will continue eating even with significant oral disease, though the way they eat may change. Watch for shifts like gulping food instead of chewing, eating only on one side of the mouth, or dropping kibble. A decrease in appetite is common in both mild and severe oral pain, but it’s not always obvious if your cat is simply eating a little less.
Other signs include persistent bad breath, drooling (sometimes tinged with blood), pawing at the face, and reluctance to be touched around the head. Some cats become withdrawn or irritable. Weight loss can develop gradually if eating becomes painful enough to reduce food intake over weeks or months. Because these signs overlap with many other conditions, periodontal disease is often only confirmed during a veterinary oral exam.
Which Cats Are Most at Risk
Age is the strongest predictor. Cats under 3 have a periodontal disease rate of about 3.6%, but that jumps to nearly 20% by ages 6 to 9 and stays above 25% from age 12 onward. The median age of cats diagnosed with periodontal disease is around 9.5 years, compared to about 5 years for unaffected cats.
Breed matters too. Flat-faced breeds are particularly vulnerable. A study of Persian and Exotic Shorthair cats found periodontal disease in 88% of the animals examined. Their shortened skulls cause tooth crowding and misalignment, which traps more plaque and makes the gumline harder to keep clean. These breeds also have higher rates of other dental problems, including tooth resorption, a painful condition where the tooth structure breaks down from the inside.
How It’s Diagnosed
A visual check of your cat’s mouth while they’re awake gives a general picture, but it consistently underestimates the problem. The most important diagnostic step happens under anesthesia: full-mouth dental X-rays combined with probing each tooth at multiple points to measure pocket depth. In a healthy cat, the probe should sink no more than 1 millimeter.
Even X-rays have limits. Bone loss doesn’t become visible on a radiograph until 30 to 50% of the mineral content is already gone, meaning the actual damage is always worse than what the images show. This is one reason veterinary dentists recommend routine dental imaging rather than waiting for visible problems.
Treatment by Stage
A professional dental cleaning, sometimes called a COHAT (comprehensive oral health assessment and treatment), follows a standardized sequence. After anesthesia, the veterinarian takes full-mouth X-rays, then scales each tooth above and below the gumline to remove plaque and tartar. The crowns are polished afterward to smooth out tiny scratches that would otherwise attract new plaque buildup. Finally, every tooth is individually probed and charted.
For Stage 1 gingivitis, a thorough professional cleaning combined with home care can fully resolve the inflammation. Once the disease reaches Stage 2 or beyond, the lost bone and attachment don’t grow back. Treatment at these stages focuses on stopping further progression. In moderate to severe cases, extraction of badly affected teeth is often the best option. Cats adapt remarkably well to having teeth removed, and most eat more comfortably afterward because the source of chronic pain is gone.
Cost varies depending on what’s needed. A straightforward cleaning with anesthesia and X-rays typically runs $200 to $400. If extractions are required, expect $600 to $1,200 for a single tooth or up to $2,000 when multiple teeth come out. Specialty veterinary dentists may charge $1,000 to $3,000 or more for complex cases.
Effects Beyond the Mouth
Periodontal disease isn’t just a dental problem. The inflamed gum tissue acts like an open wound, giving bacteria a direct route into the bloodstream. In humans, the link between gum disease and heart, kidney, and liver damage is well established, and veterinary researchers have identified similar patterns in cats. Chronic low-grade inflammation from the mouth places ongoing stress on the immune system and can contribute to organ damage over time, particularly in older cats whose kidneys or hearts are already compromised.
Prevention and Home Care
Daily toothbrushing is the single most effective thing you can do. Using a small, soft-bristled brush or a finger brush with pet-safe toothpaste disrupts plaque before it hardens. Even brushing every other day makes a meaningful difference compared to no brushing at all. The key is consistency, and starting when your cat is young makes acceptance much easier.
For cats that won’t tolerate a toothbrush, several products have earned the Veterinary Oral Health Council (VOHC) seal, meaning they’ve been independently tested and proven to reduce plaque, tartar, or both. Options include dental-specific diets from brands like Hill’s, Purina, and Royal Canin, which use kibble size and texture to mechanically scrub teeth. Water additives (like Healthymouth) can reduce plaque accumulation passively. Dental treats such as Greenies Feline Dental Treats and Purina DentaLife target tartar reduction.
None of these products replace professional cleanings, but they slow the rate at which plaque and tartar accumulate between visits. The VOHC maintains a full list of accepted products on their website, which is worth checking since many pet dental products on store shelves have no independent testing behind their claims.