Oral Cavity and Dental Disease in Cats
April 25, 2018
Oral and Gum Disease (Periodontal Disease, Gingivitis, Stomatitis)
Cats can develop problems in the tissues around their teeth just like us! The oral cavity includes the supportive periodontal tissues of the teeth, as well as the salivary glands and immune tissues (such as tonsils).
Mild or early gum disease often shows up as an intense red line and/or swelling along the teeth at the gumline. This is termed gingivitis. When gum infection or inflammation becomes more advanced, the anchoring soft tissues and eventually, the bony sockets can become weak and degraded, leading to loose, lost, or abscessed teeth (periodontitis). Signs of periodontal disease include red swollen gums, receding or overgrown gumline, supra-erupted (‘snaggle’) teeth, purulent discharge (pus) and bad breath (halitosis). Signs progressively worsen as periodontal disease advances from gingivitis to periodontitis.
Stomatitis is a widespread immune-mediated deep inflammatory condition of the gums and soft tissues of the oral cavity. It especially affects those parts outside of the palatoglossal folds (arcs of tissue adjacent to the soft palate). The cause of stomatitis is not well understood.
STOMATITIS RISK FACTORS
Chronic viral infection, including upper respiratory viruses such as Herpesvirus and Calicivirus, and immune system suppressing viruses such as Feline Immunodeficiency Virus (FIV) or Feline Leukemia Virus (FeLV) may play a role in and complicate response to stomatitis treatment(s). Regardless of the inciting causes, none of which have been well proven, the affected cats’ immune system overreacts to plaque bacteria, and/or the tooth or tooth’s supportive tissues, leading to severe and often debilitating inflammation (stomatitis).
“Whole mouth” tooth extractions are the mainstay of stomatitis treatment, and this procedure prevents the need for ongoing medications in over 95 per cent of stomatitis cases. This is true especially for those cats without pre-existing immune system compromise (viral infection) or excess bumpy (proliferative) tissues. Proliferative tissues may be smoothed and scarred during treatment to prevent pain and debris/antigen-trapping using carbon dioxide (CO2) laser. Full mouth extractions and oral laser treatments are generally performed by veterinarians with advanced training in veterinary dentistry and oral surgery.
Tooth Disease; Role of Tartar and Plaque and Tooth Resorption
Cats do not develop “cavities” like humans, other primates, dogs, and bears do. However, cats do get holes in their teeth as a result of tooth resorption rather than classic cavity decay. Tooth resorption (TR) lesions appear tooth-coloured, but may appear red when inflamed gum tissue moves up onto the tooth, and “Band-Aids” or covers tooth defects above the gumline on the tooth. In cats, TR lesions are most commonly seen at or above the gumline in teeth other than the canines/fang teeth (these teeth usually have lesions at or below the gumline only detectable on X-ray). In cats, TR lesions were previously termed neck lesions or FORLs (feline odontoclastic resorptive lesions) and misnamed “cat cavities”. Tooth Resorption (TR) is the only American Veterinary Dental College Nomenclature Committee accepted term for these lesions. More information can be found here: http://www.avdc.org/Nomenclature/Nomen-Intro.html#Contents.
Tooth resorption weakens teeth and frequently leads to shearing off of the tooth or part of the tooth at the gumline. Supragingival (above the gumline) TRs are very painful, though cats will rarely show their caregiver signs of pain. Difficulty eating, excess drool (salivation), partial or complete tooth loss, or teeth that are loose, face rubbing, and bad breath (halitosis) are possible signs of tooth resorption.
Given how rarely affected cats exhibit signs of pain, and the fact that these lesions do not cause periodontal or endodontic disease, these TR lesions can go undetected without a detailed oral examination and full mouth dental X-rays.
TR RISK FACTORS
In the last 50 years or so, the number of cats affected by these lesions has apparently increased, likely secondary to improved veterinary education and more veterinary dental units in use in veterinary clinics. Research continues into the exact cause of resorptive lesions, though overactive bone resorption cells (odontoclasts) are a consistent feature of TR changes. Disease of the gums and periodontal structures is a known to accompany tooth resorption, but is not always its cause. Diet, genetics (intrinsic calcium: phosphorus balance), and tooth damage may also play a role in TR development but none of these have been proven.
In one reported survey, authors Wessum and others (1992) looked at TR’s in living cats from Holland and the United States. TRs were quite prevalent, with 62 per cent of the Netherland cats and 67 per cent of the American cats afflicted. These percentages are underestimated given failure to perform full mouth X-rays in all studies on all cats. X-rays are necessary to detect early lesions, and those below the gumline. If attempts were made to fix TR teeth, researchers reported that three-quarters of the restored teeth deteriorated because the unknown cause of resorption was not remedied, but the teeth merely patched.
If disease is already underway, therapy depends on the nature of the problem and the severity at the time of diagnosis. In most cases, a full dental/oral cavity exam including full mouth dental X-rays and teeth cleaning under general anaesthesia will allow the veterinarian to chart and objectively document dental changes. The nature of these changes as well as the overall systemic and oral health of the patient dictates whether extraction or crown amputation-intentional root retention, and/or other therapeutics are performed. Immune compromise such as FeLv/FIV, diabetes, chemotherapy, stomatitis necessitate complete tooth extraction. Dental X-rays are an important component of diagnosis for problems that lurk below the gumline.
Prevention of oral cavity problems in cats requires home dental care. Preventive measures include regular tooth brushing at home, water additives, dental gels, fatty acid supplementation, and prescription dental diets. Ongoing early research in TRs may support feeding non-acidifying diets with higher magnesium, potassium, calcium, and phosphorus content. More definitive recommendations for TR will have to await further research.
Talk to your veterinarian about the benefits of regular dental home care for your cat, as well as the timing of professional interventions. As a general rule, any hardened plaque (calculus/tartar), halitosis, oral tissue discolouration, soft or hard tissue changes including prominences (swelling, proliferative), or perceived signs of oral pain warrant COHAT (Complete Oral Health Assessment and Treatment) by a licensed veterinarian. Licensed veterinarians may refer their clients to veterinarians with a special interest in, or specialty certification in veterinary dentistry for more advanced treatment options.
Kathleen Cavanagh, BSc DVM MET, Consulting Online Editor CVMA
Lee Jane Huffman, DVM, Dip. AVDC, Consulting Specialist Editor
April 16, 2018
Reiter, A.M. Lewis JR Okuda A. (2005) Update on the etiology of tooth resorption in domestic cats. Vet Clin North Am Small Anim Pract. Jul 35(4):913-42.
Nicolas Girard, Eric Servet, Food Ing; Philippe Hennet, Vincent Biourge. (2011). Tooth Resorption and Vitamin D3 Status in Cats Fed Premium Dry Diets. J Vet Dent 27 (3):142-47.
van Wessum R, Harvey CE, Hennet P. (1992) Feline Dental Resorptive Lesions: Prevalence Patterns. Vet Clin North Am Small Anim Pract. 22(6): 1405-1416. Online January 2015 http://dx.doi.org/10.1016/S0195-5616(92)50134-6