Gum Disease

Bacterial infection of the tissue surrounding the teeth causes inflammation of the gums, the ligaments that anchor the teeth, and the surrounding bone. If gum (periodontal) disease goes untreated, teeth can be lost due to the loss of their supporting tissues. This is the major reason for tooth loss in dogs.

Gum disease is caused by accumulation of bacteria (plaque) at the gum line due in part to a lack of proper oral hygiene. Other contributing factors may include breed, genetics, age, and diet. As the number of bacteria below the gumline increases, bacterial waste products such as hydrogen sulfide, ammonia, acids, and other compounds accumulate and damage tissues. The dog’s own response to this infection also causes tissue breakdown and loss of the tooth’s supporting tissues. There are 2 forms of gum disease: gingivitis and periodontitis.

Gingivitis

In gingivitis, the gums become inflamed because of bacterial plaque, but the ligaments and bone are not yet affected. The gums change in color from coral-pink to red or purple, and the edge of the gum swells. The gums tend to bleed on contact. Bad breath is common. Gingivitis can be reversed with proper tooth cleaning but, if untreated, may lead to periodontitis (see below).

Gingivitis usually can be treated by thorough professional cleaning of the teeth. This should include cleaning below the gum line. If gingivitis does not improve, the dog should be examined again in case more extensive cleaning is required. When cleanings are completed, your veterinarian may apply a sealant to the teeth to prevent bacterial buildup and improve healing. Dogs that do not respond to treatment should be evaluated for other disease such as immune system problems and diabetes. Gingivitis will reoccur if the teeth are not kept clean and free of plaque. Therefore, at-home oral hygiene methods such as brushing as well as regular cleanings by your veterinarian are important.

Periodontitis

In periodontitis, the tissue damage is more severe and includes the gums, ligaments, and bone. It usually is seen after years of development of plaque, tartar, and gingivitis. It is irreversible and results in permanent loss of tooth support. Smallbreed dogs usually experience more problems with periodontitis than large-breed dogs. Dogs that have a regular diet of hard kibble develop fewer problems due to the mechanical cleaning effect on the teeth as the food is chewed. Back teeth are affected more often than front teeth. The upper teeth are affected more severely than the lower teeth, and the cheek surfaces of the teeth have more disease than the surfaces near the tongue. Gingivitis is often first noticed at about 2 years of age but improves if treated. Periodontitis usually begins at 4 to 6 years of age and, if untreated, progresses to tooth loss.

Periodontitis is treated with thorough professional cleaning above and below the gum line. In some cases, surgery will be needed to gain access to the root surface for cleaning. Teeth can generally be saved until they have lost about 66% of their bone support from one or more of their roots. Your veterinarian can determine the extent of bone support loss by taking x-rays of the jaws. These are usually recommended as a normal part of periodontal disease diagnosis and treatment planning. If your dog has been treated for periodontitis, you will need to continue oral hygiene care at home. Follow your veterinarian’s instructions, which might include daily toothbrushing, dietary changes, plaque prevention gel, and oral rinses. Regular (every 6 months to 1 year) preventive cleanings will help to avoid relapse and prevent further bone loss.

The Merck/Merial Manual for Pet Health. Copyright© 2007 by Merck & Co., Inc.,
Whitehouse Station, NJ, USA. All rights reserved.