Stages of Gingivitis in Cats: What Each Stage Looks Like and What to Do

The stages of gingivitis in cats run from healthy gums to advanced gum disease. Vets use five stages, PD0 to PD4, and only the early gingivitis stage is reversible.

This guide explains the stages of gingivitis in cats in plain words. You will see what each stage looks like, whether gum disease can spread between cats, and what you and your vet can do at each step.

What are the stages of gingivitis in cats?

First, gingivitis means inflammation of the gums. The American Veterinary Dental College defines it simply as inflammation of the gingiva.

If plaque stays on the teeth, then the inflammation can spread deeper. Then it reaches the ligament and bone that hold each tooth. Vets call this deeper stage periodontitis.

So when owners ask about the stages of gingivitis in cats, they usually mean the full scale of periodontal disease. Vets stage each tooth on its own, because one tooth can be healthy while the next one is not.

Here is the key point about the stages of gingivitis in cats. According to VCA Animal Hospitals, gingivitis is the earliest and only reversible stage of periodontal disease. The Cornell Feline Health Center agrees that gingivitis is usually reversible, while periodontitis is not.

The 5 stages of gingivitis in cats at a glance

This table lines up the stages of gingivitis in cats with the official AVDC and AAHA terms.

The AAHA staging guide uses the same percentages. It calls stage 2 early disease, stage 3 established disease and stage 4 advanced disease.

Stage 0 and stage 1: healthy gums and early gingivitis

At stage PD0, the first of the stages of gingivitis in cats, the gums look normal. There is no visible inflammation and no loss of tooth support.

Stage PD1 is where most of the stages of gingivitis in cats begin. AVDC describes it as gingivitis only, without attachment loss. In other words, the gums react to plaque, but the bone and ligament are still fine.

VCA describes gingivitis as redness and swelling along the gum line where the gum meets the tooth. Bad breath is common, and the gums often bleed when you brush.

This is the stage to act on, because it is the only one of the stages of gingivitis in cats you can reverse. With a vet cleaning and steady home care, the gums can heal. Our guide on how often to brush cat teeth explains a routine that helps keep plaque down.

What do the stages of gingivitis in cats look like?

Many owners search for photos of the stages of gingivitis in cats. While every cat differs, vets often grade gum redness with a simple scale.

For example, one common tool is the gingival index from Löe and Silness. WikiVet lists four grades.

• Grade 0. Healthy gums with no redness.
• Grade 1. Mild gingivitis, with slight redness and swelling and no bleeding on gentle probing.
• Grade 2. Moderate gingivitis, with red, swollen gums that bleed on gentle probing.
• Grade 3. Severe gingivitis, with very swollen, red or bluish-red gums that may bleed on their own or ulcerate.

At home, you will mostly notice the early stages of gingivitis in cats as redness, a puffy gum edge and bad breath. Cornell adds that cats with sore gums may eat with caution, drool or paw at the mouth. If you want more detail on gum color, read our guide to red gums in cats.

Stage 2: early periodontitis in the stages of gingivitis in cats

At stage PD2, the problem has moved past the gums, so the stages of gingivitis in cats now involve bone. AVDC defines it as early periodontitis with less than 25% loss of tooth support.

For example, you may see more tartar, deeper redness and some bleeding. However, the changes under the gum line are hard to see at home. That is why vets probe each tooth and take X-rays.

This stage cannot fully reverse, because lost support does not grow back on its own. Still, a vet cleaning and daily care can slow it down and protect the other teeth.

Stage 3 and stage 4: moderate and advanced disease

Next, stage PD3 means 25% to 50% loss of tooth support. Stage PD4 means more than 50% loss. These are the most serious stages of gingivitis in cats, and by now the disease is periodontitis.

At these late stages of gingivitis in cats, gums may pull back from the teeth. Teeth may wobble, and the mouth often hurts. Some cats stop eating dry food, while others chew on one side.

As a result, many teeth at stage 4 need removal. That may sound harsh, but removing a painful tooth ends the source of pain. Your vet will explain the options for each tooth.

Can the stages of gingivitis in cats spread between cats?

This is a common worry about the stages of gingivitis in cats in multi-cat homes. The answer has two parts, so let us take them in turn.

First, plaque causes most gingivitis. VCA links it to plaque bacteria and to poor oral hygiene. We found no source that says plaque gingivitis passes from one cat to another, so the gum disease itself is not usually treated as contagious.

Second, some infections can trigger gum disease. Cornell lists feline leukemia virus, feline immunodeficiency virus and feline calicivirus among the triggers. Cornell's Baker Institute calls calicivirus a highly contagious virus that spreads through saliva, nasal mucus and eye discharge, and also through bowls, litter boxes and bedding.

The same page notes that some cats with calicivirus develop a chronic form of gingivitis with thick, inflamed gums. However, the link with severe mouth inflammation is still a correlation, not a proven cause. A 2017 study of 104 cats states that no study has yet shown a direct causal link between calicivirus and chronic gingivostomatitis.

So the safe summary is this. Plaque gingivitis does not jump between cats, but some viruses linked to gum inflammation do. Ask your vet about vaccines and testing if you have several cats.

Gingivitis vs stomatitis

However, stomatitis is different from the usual stages of gingivitis in cats. Cornell describes it as inflammation or sores in other parts of the pink lining of the mouth, not just the gums.

However, it is much less common than the usual stages of gingivitis in cats. Cornell estimates that the gingivitis and stomatitis syndrome affects about one in 100 cats. The Cornell gingivostomatitis page adds that about 60% of cats need no further medical care after full-mouth extraction.

Also, in the 2017 study of 104 cats with this condition, 13.5% tested positive for FIV and none tested positive for FeLV. The authors describe the disease as multifactorial.

Young cats and juvenile gingivitis

Some young cats move through the stages of gingivitis in cats early. A VIN article on juvenile gingivitis notes that inflammation can start as early as the time the adult teeth erupt. It is often diagnosed between 6 and 12 months of age.

Also, Maine Coon and Siamese cats appear more often in these cases. Also, Clinician's Brief warns that untreated juvenile gingivitis may progress to periodontitis. See our guide to juvenile periodontitis in cats for more.

How common are the stages of gingivitis in cats?

Gum disease is very common. A RVC VetCompass study of 18,249 UK cats found that vets diagnose periodontal disease in 15.2% of cats each year, which made it the most common disorder in that study.

Also, age raised the risk sharply. Cats aged 9 to 12 were 6.7 times more likely to have periodontal disease than cats under 3. Siamese cats had the highest rate in the study, at 18.7%.

Exam-based estimates run higher, since vets find more when they look closely. The Cornell Feline Health Center estimates that periodontal disease affects about 85% of cats over age six.

How vets confirm the stages of gingivitis in cats

You can spot red gums at home, but you cannot see the bone. So vets confirm the stages of gingivitis in cats with a full exam under anesthesia.

During that exam, the vet first measures the gum pocket around each tooth with a thin probe. Then dental X-rays show the bone and the roots. Together, these steps show how much support each tooth has lost.

Cornell explains that a complete exam means looking at the teeth under general anesthesia and taking X-rays when needed. Because of this, two cats with the same red gums can end up at very different stages.

Home checks for the stages of gingivitis in cats

A short weekly check helps you catch the early stages of gingivitis in cats. First, pick a quiet moment after a meal. Next, lift the upper lip at the side and look at the gum line above the big back teeth.

Then look for a red or puffy edge, brown tartar, or gums that pull back. Also, smell the breath, since a strong odor often comes with early gum disease. If you notice any of these signs, write down the date and book a vet visit.

Keep each check short, and then reward your cat. Over time, your cat will learn to accept it, and that makes brushing easier too.

What to do at each of the stages of gingivitis in cats

1. Lift your cat's lip once a week and look for redness, swelling or tartar.
2. Book a vet visit if you see changes, bad breath or eating trouble.
3. Let your vet stage each tooth with an exam under anesthesia and X-rays.
4. Follow the treatment plan, which may include cleaning or extractions.
5. Keep up daily home care, since plaque returns within days.

The AVMA explains that a vet cleaning under anesthesia includes scaling to remove plaque and tartar, followed by polishing. It also notes that X-rays may help assess the bone and roots below the gum line.

At home, brushing gives the best results at every one of the stages of gingivitis in cats. Cornell advises using cat toothpaste only, and asking your vet before you brush a cat with severe gingivitis. If your cat will not accept a brush, see our guide to cat teeth without brushing.

A daily powder can be part of the routine too. Kittysum Dental+ is a daily nutrition support powder that mixes into food. It does not treat gum disease, so use it with brushing and vet care, not instead of them.

Finally, keep your vet visits regular. A yearly check catches early gum changes before they become painful, and your vet can tell you how often your cat needs a cleaning.

Myths about the stages of gingivitis in cats

• Myth: red gums always mean a virus. Plaque causes most gingivitis, so a dental exam comes first.
• Myth: gum disease always shows. Much of the damage sits under the gum line, so X-rays matter.
• Myth: antibiotics fix gingivitis. Cornell notes that antibiotics alone have little support, because the plaque stays behind.
• Myth: a cat that eats is pain-free. Cats hide mouth pain well, so watch for subtle changes.

For the full picture of gum care, read our main guide to cat gingivitis. To learn which teeth your vet is charting, see the cat dental formula. Bad breath has its own guide too, on cat bad breath.

Related guides: Cat gums · Is cat gingivitis contagious?

Key Terms

• Gingivitis: inflammation of the gums, the only reversible stage of periodontal disease.
• Periodontitis: inflammation of the deeper tissues, including the ligament and bone that hold a tooth.
• Attachment loss: the loss of tissue that anchors a tooth, which vets measure to set the stage.
• Gingival index: a 0 to 3 scale that grades gum redness, swelling and bleeding.
• Stomatitis: inflammation or sores in the lining of the mouth beyond the gums.