# Periodontal Disease in Cats: Stages, Signs and Causes Periodontal disease in cats stages progress from early gum inflammation to irreversible bone loss around the teeth. Stage 1 gingivitis can be reversed with professional cleaning and home care, but once bone is lost in later stages, it does not grow back. Knowing what each stage looks like helps you get your cat treated before damage becomes permanent. This article is educational and is not a substitute for veterinary diagnosis or treatment. ## Quick Answer - Periodontal disease is the most common oral condition in cats, affecting over 80% of cats by three years of age [1]. - Stage 1 is gingivitis only. The gums are red, swollen, and may bleed, but the ligaments and bone that hold the teeth are not yet affected [2]. - Gingivitis is reversible with proper tooth cleaning. Periodontitis, which involves bone loss, is not reversible [2][3]. - Bad breath, red gums, dropping food, and chewing on one side are the signs owners notice most often [2][4]. - Daily tooth brushing is the single most effective home prevention step [1]. ## What Periodontal Disease in Cats Actually Is Periodontal disease is infection and inflammation of the tissue surrounding the teeth [2]. That tissue includes the gums, the ligaments that anchor each tooth in its socket, and the bone that supports the tooth roots. When bacteria build up as plaque at and below the gum line, the immune system reacts, and that reaction damages the very tissues holding the teeth in place [2]. There are two forms. Gingivitis is inflammation of the gums alone. Periodontitis is the more advanced form where the ligaments and bone are involved [2]. The distinction matters because gingivitis can be reversed. Periodontitis cannot. Plaque forms constantly on cat teeth. If it is not regularly removed, it migrates deeper toward where the gum meets the base of the tooth, and eventually below that point into the subgingival region [5]. Once bacteria are established under the gum line, the immune system mounts a response that causes inflammation and pain [5]. Some researchers believe gingivitis starts when the bacterial populations in plaque shift from normal, healthy species to disease-causing species [5]. ## Signs of Periodontal Disease in Cats Cats are good at hiding oral pain. Many keep eating right up until the disease is advanced. That is one reason dental disease is so often missed at home. ### What you may notice at home - Bad breath (halitosis) is one of the earliest and most common signs [2][4]. - Gums that look red or purple instead of coral pink, with a swollen edge along the teeth [2]. - Gums that bleed when you touch them or when your cat eats hard food [2]. - Yellow or brown tartar (calculus) along the gum line [4]. - Dropping food, chewing on one side, or preferring soft food. - Pawing at the mouth, drooling, or flinching when you touch the face. - Weight loss or a dull coat if eating becomes painful [5]. In many cases, dental disease causes a cat to stop eating, which leads to a variety of other health problems [5]. Dental disease can cause serious pain and discomfort that affects a cat's quality of life [5]. ### Signs you cannot see Gingival recession (gums pulling away from the teeth), periodontal pockets, bone loss, furcation exposure (where the space between roots becomes exposed), and loose teeth are all part of the disease but require a veterinarian to detect [4]. You will not see these at home. That is why regular professional exams matter even when the mouth looks fine to you. ## Periodontal Disease in Cats Stages Veterinarians stage periodontal disease based on how much of the tooth's supporting structure has been lost. The staging system runs from 0 to 4. Here is what each stage means in plain terms. | Stage | What is happening | What you may see at home | Reversible? | |---|---|---|---| | 0 (Healthy) | Gums are coral pink, no inflammation | Normal breath, no tartar | N/A | | 1 (Gingivitis) | Gum inflammation only, ligaments and bone unaffected [2] | Red gum edge, bad breath, bleeding on contact [2] | Yes, with cleaning [2] | | 2 (Early periodontitis) | Up to 25% of attachment lost, early bone loss | Bad breath, tartar, red gums, possible discomfort eating | No, bone loss is permanent | | 3 (Moderate periodontitis) | 25 to 50% of attachment lost | Dropping food, chewing on one side, visible gum recession | No | | 4 (Advanced periodontitis) | More than 50% of attachment lost, loose teeth possible [6] | Difficulty eating, weight loss, severe tartar, mobile teeth | No, extractions often needed | Stage 1 is the only stage where the disease can be fully reversed [2]. In gingivitis, the gums become inflamed because of bacterial plaque, but the ligaments and bone are not yet affected [2]. Proper tooth cleaning reverses it. If untreated, gingivitis may lead to periodontitis [2]. Stage 2 is where things change permanently. Once the ligaments and bone that anchor the tooth begin to break down, that support does not regenerate on its own. The goal of treatment shifts from reversal to stopping progression and managing pain. Stage 4 often means extractions. In one reported case, a cat with stage 4 periodontal disease and tooth resorption needed multiple extractions, and afterward the cat's appetite, body condition, energy levels, and coat quality all improved [6]. ## Causes and Risk Factors The root cause is bacterial plaque. Periodontal disease is caused by the accumulation of many different bacteria at and below the gum line, due in part to a lack of proper oral hygiene [2]. It is a multifactorial condition characterized by inflammation and bone loss [7]. Several things increase a cat's risk: - **Age.** Periodontal disease becomes more common as cats get older. It affects up to 90% of older cats [8]. - **Lack of home dental care.** Without regular plaque removal, bacteria keep accumulating [2][5]. - **Tooth crowding.** Crowded teeth trap plaque and make it harder to clean [5]. - **Diet consistency.** Diet consistency is a recognized risk factor for disease susceptibility [1]. - **Breed and genetics.** Risk factors such as breed size are examined in relation to disease susceptibility [1]. - **Immune response.** If a cat's immune response to disease-causing bacteria is strong, gingivitis develops. Some cats tolerate the same bacteria without damage [5]. The bacteria involved are specific. Cats with periodontitis show shifts in their oral microbiome, with expansion of Bacteroidota and Spirochaetota and enrichment of Treponema, Peptostreptococcus, Filifactor, and Fusobacterium nucleatum [8]. Porphyromonas gulae is one of the key bacteria linked to severe gingivitis, halitosis, and bone destruction in cats [3]. Periodontal disease is not just a mouth problem. It has been associated with an increased risk of chronic azotemic kidney disease [4]. It also has systemic effects, including impact on organ health and interaction with endocrine diseases [4]. In one case, a cat with chronic diarrhea improved after its periodontal disease was treated, which suggests a link between oral and gastrointestinal health [6]. ## How Veterinarians Diagnose It Diagnosis starts with a visual exam of the mouth, but that is only the beginning. A full diagnosis requires periodontal probing and dental radiography to assess how much attachment loss is present around each tooth [4]. Probing measures the depth of pockets between the gum and tooth. Radiographs (dental X-rays) show bone loss that cannot be seen with the naked eye. This is why a dental cleaning under anesthesia is more than a cosmetic procedure. Your veterinarian cannot properly examine below the gum line or take meaningful X-rays on an awake cat. Treatments performed without anesthesia may make the tooth look better but do not treat the underlying problem, which is plaque below the gum line [2]. ## Treatment Options Treatment depends on the stage. For gingivitis (stage 1), a professional dental cleaning by your veterinarian is the core treatment. This requires anesthesia [2]. Cleaning removes plaque and calculus above and below the gum line, allowing the gums to heal. With proper follow-up care at home, gingivitis can be reversed [2]. For periodontitis (stages 2 to 4), treatment includes professional dental cleaning plus cleaning of the root surface or periodontal pocket with gingival curettage, with or without creating a periodontal flap [4]. In simpler terms, your veterinarian cleans deep under the gums where the infection lives. Severely affected teeth may need extraction. Anesthesia-free dental cleanings are not a substitute. They may improve appearance but leave the actual disease untreated [2]. Pain management matters. In the stage 4 case described earlier, the cat received multimodal analgesia including locoregional dental blocks during extractions [6]. Ask your veterinarian about pain control before and after any dental procedure. For a deeper look at treatment options, see [How To Treat Periodontal Disease In Cats](/knowledge/veterinary-medicine/clinical-methods/how-to-treat-periodontal-disease-in-cats) and [How To Treat Dental Disease In Cats](/knowledge/veterinary-medicine/dental-care/how-to-treat-dental-disease-in-cats). ## Recovery, Outlook, and Long-Term Management The outlook depends on how early you catch it. Stage 1 gingivitis has an excellent outlook. With professional cleaning and consistent home care, the gums can return to normal [2]. Stages 2 through 4 have a guarded outlook for the affected teeth. Bone loss is permanent. The goal becomes slowing progression, controlling pain, and preserving as many teeth as possible. Some teeth will need to come out. Cats often do better after treatment than owners expect. In the reported case of a cat with stage 4 disease, appetite, body condition, energy levels, and coat quality all improved after extractions and pain management [6]. Cats can eat well without most or all of their teeth. Long-term management usually means: - Professional dental cleanings at intervals your veterinarian recommends. - Daily home plaque control. - Monitoring for new signs like bad breath returning or changes in eating. - Watching for related conditions. Tooth resorption and feline chronic gingivostomatitis are other common oral diseases in cats, and they can occur alongside periodontal disease [5][9]. For more on these, see [Feline Oral Disease: Stomatitis, Periodontal Disease, and Tooth Resorption](/knowledge/veterinary-medicine/clinical-methods/feline-oral-disease-stomatitis-periodontal-disease-tooth-resorption). ## Prevention Prevention is the most effective strategy because periodontal disease is irreversible once bone loss starts [3]. **Brush your teeth daily.** Daily tooth brushing is a current best practice in prevention [1]. Use a cat-safe toothpaste and a soft brush. If your cat will not tolerate brushing, ask your veterinarian about alternatives. **Use veterinary dental products.** Dental chews, antiseptic rinses, and barrier sealants are reviewed as evidence-based prevention strategies [1]. Look for products accepted by the Veterinary Oral Health Council. **Schedule regular professional exams.** Your veterinarian can detect problems before you see them at home. Early detection at stage 1 is the difference between a reversible problem and a permanent one. **Feed an appropriate diet.** Diet consistency is a risk factor for disease susceptibility [1]. Ask your veterinarian whether your cat's diet supports oral health. **Do not rely on anesthesia-free cleanings.** They do not treat plaque below the gum line, which is where the disease actually lives [2]. For a broader overview of dental disease across species, see [Dental Disease In Dogs And Cats](/knowledge/veterinary-medicine/dental-care/dental-disease-in-dogs-and-cats). ## Limitations and When to Contact a Veterinarian This article gives general information. Every cat is different, and individual cases need a veterinarian who can examine your cat's mouth, take X-rays, and recommend treatment based on what is actually happening. **Contact your veterinarian the same day if your cat:** - Stops eating or drinking - Drops food repeatedly or cries while eating - Has visible bleeding from the mouth - Has swelling around the face or jaw **Go to an emergency clinic now if your cat:** - Has trouble breathing - Has a swollen eye or swelling that is rapidly getting worse - Is unable to close the mouth - Collapses or seems severely weak **Schedule a routine visit if your cat:** - Has bad breath that has gotten worse - Has visible tartar or red gums - Has not had a dental exam in the past year - Is eating less than usual or losing weight slowly ## Frequently Asked Questions ### Can gingivitis in cats be cured? Yes, gingivitis can be reversed with proper tooth cleaning [2]. The gums are inflamed but the ligaments and bone are not yet affected, so healing is possible. Once periodontitis develops and bone is lost, the damage is permanent. ### What does stage 2 periodontal disease mean for my cat? Stage 2 means early periodontitis with up to about 25% of the tooth's attachment lost. The bone loss is permanent, but treatment can slow or stop further progression. Your veterinarian will likely recommend a professional cleaning under anesthesia and may discuss extractions for the worst affected teeth. ### How do I know if my cat has dental pain? Cats often hide dental pain and may keep eating normally until disease is advanced. Signs to watch for include dropping food, chewing on one side, pawing at the mouth, drooling, and flinching when the face is touched. A veterinarian can examine the mouth properly and take X-rays to find problems you cannot see. ### Is anesthesia-free dental cleaning safe for my cat? Anesthesia-free cleanings may make the teeth look better but do not treat the underlying problem, which is plaque below the gum line [2]. They are not a substitute for a professional cleaning under anesthesia. Your veterinarian can discuss anesthesia safety and what monitoring is used. ### How often should my cat have a dental exam? Most cats benefit from a professional dental exam at least once a year, though your veterinarian may recommend more frequent visits if your cat has a history of dental disease. Daily tooth brushing at home is the most effective prevention between visits [1]. Ask your veterinarian to set a schedule based on your cat's specific needs. ## Related Articles - [How To Treat Periodontal Disease In Cats](/knowledge/veterinary-medicine/clinical-methods/how-to-treat-periodontal-disease-in-cats) - [Dental Disease In Dogs And Cats](/knowledge/veterinary-medicine/dental-care/dental-disease-in-dogs-and-cats) - [Feline Oral Disease: Stomatitis, Periodontal Disease, and Tooth Resorption](/knowledge/veterinary-medicine/clinical-methods/feline-oral-disease-stomatitis-periodontal-disease-tooth-resorption) - [How To Treat Dental Disease In Cats](/knowledge/veterinary-medicine/dental-care/how-to-treat-dental-disease-in-cats) - [Dog Dental Disease: Signs, Stages, and What You Can Do](/knowledge/veterinary-medicine/preventive-and-routine-care/dog-dental-disease-signs-stages-and-what-you-can-do) - [Pet Dental Disease Signs](/knowledge/veterinary-medicine/dental-care/pet-dental-disease-signs) ## References 1. [Overview of Periodontal Disease in Dogs and Cats](https://pubmed.ncbi.nlm.nih.gov/41712493/). Journal of veterinary dentistry, 2026. 2. [Dental Disorders of Cats - Cat Owners](https://www.merckvetmanual.com/cat-owners/digestive-disorders-of-cats/dental-disorders-of-cats). Merck Veterinary Manual. 3. [Oral treatment with catechin isolated from Japanese green tea significantly inhibits the growth of periodontal pathogen Porphyromonas gulae and ameliorates the gingivitis and halitosis caused by periodontal disease in cats and dogs](https://pubmed.ncbi.nlm.nih.gov/39693953/). International immunopharmacology, 2025. 4. [Periodontal Disease in Small Animals - Digestive System](https://www.merckvetmanual.com/digestive-system/dentistry-in-small-animals/periodontal-disease-in-small-animals). Merck Veterinary Manual. 5. [Feline Dental Disease](https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/feline-dental-disease). Cornell University College of Veterinary Medicine. 6. [Resolution of Chronic Diarrhoea Following Treatment of Periodontal Disease in a Cat](https://pubmed.ncbi.nlm.nih.gov/41828967/). Animals : an open access journal from MDPI, 2026. 7. [Impact of Periodontal Disease on the Oral Microbiome of Cats](https://pubmed.ncbi.nlm.nih.gov/40295327/). Current microbiology, 2025. 8. [Alterations in the feline oral microbiome in common oral diseases - A comprehensive review](https://pubmed.ncbi.nlm.nih.gov/42566284/). European journal of microbiology & immunology, 2026. 9. [Case Report: Shift from Aggressive Periodontitis to Feline Chronic Gingivostomatitis Is Linked to Increased Microbial Diversity](https://pubmed.ncbi.nlm.nih.gov/40137713/). Pathogens (Basel, Switzerland), 2025. ## Further Reading - [Merck Veterinary Manual: Cat Owners](https://www.merckvetmanual.com/cat-owners) - [Cornell Feline Health Center: Health Information](https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information) - [American Veterinary Medical Association: Pet Care](https://www.avma.org/resources-tools/pet-owners/petcare)