With FSG, cats become allergic to plaque. Photo by Dr. Jan Bellows

What is it?

Feline gingivostomatitis (FGS) is a severe, painful oral disease that affects some cats where the cat’s mouth becomes allergic to plaque on the teeth and tongue and gums. The allergic response appears as striking inflammation throughout the mouth.

What causes it?

Plaque bacteria is the specific cause. What is unknown is why some cats get the disease and others that have plaque do not.  The disease does not appear to be related to feline leukemia virus, feline immunodeficiency virus, sex, spaying or neutering, or diet.

What are the signs of FGS?

Severe inflammation around the teeth and the back of the mouth exists with FGS. Affected cats may drool, have really bad-smelling breath and have difficulty chewing hard food. Mouth pain may also cause a decrease in self grooming, resulting in a scruffy hair coat.

Feline gingivostomatitis causes inflammation. Photo by Dr. Jan Bellows

How is it diagnosed?

An examination usually reveals inflammation completely surrounding the teeth. The upper and lower cheek teeth are most commonly affected. In some cases, the canines and incisors as well as the back of the mouth are also involved.  

How is FGS treated?

Treatment is surgical. After the affected teeth are removed (usually those behind the canines) in the upper and lower jaws, most cases heal.  In some cats all the teeth need to be removed.  Twenty percent of the cats treated will not heal with surgery alone, and for those cats laser treatment and medication usually bring relief.

What is the prognosis?

After the teeth are extracted, the prognosis is excellent in most cases.  Fortunately domestic cats do not need their teeth to live a great long life.