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Stomatitis in Cats and Dogs

Stomatitis is a catch-all term used for an inflammation of the mouth. Stoma is the medical term for any opening in the body, and -itis refers to inflammation. There are several different terms used for stomatitis: ulcerative stomatitis, idiopathic stomatitis, lymphocytic plasmacytic stomatitis, or chronic ulcerative paradental stomatitis. The difference between these is very small and is usually related to the type of inflammation.

Stomatitis is more common in cats than dogs, but no matter what species is affected, it can be very painful and cause a decrease in an animal’s quality of life.

This type of inflammation can either be an acute or chronic disease. Patients with acute disease usually present with inflammation of the gums only (gingiva). This type of periodontal disease can usually be resolved by a full dental cleaning and consistent home dental care.

Chronic stomatitis is an inflammation of the oral cavity which causes the body to mount an immune response. Animals with chronic stomatitis usually have more extensive inflammation, including inflammation of the gums, cheeks, tongue, lining of the throat, and lips. This condition will not be resolved with a simple dental cleaning, and a more intense treatment is needed.

Causes of Stomatitis

There are many factors that can contribute to stomatitis, but there has not been one common element identified as the cause. Many animals who are affected with stomatitis also have gingivitis and/or plaque buildup. It seems that some animals have a hypersensitivity or allergic reaction to even small amounts of plaque and that is a major contributing factor to inflammation.

Stomatitis may also be indicative of a larger disease process. There may be a combination of factors present in a patient with stomatitis, making it more difficult to pinpoint a cause.

Suspected causes of stomatitis include:

Unfortunately, stomatitis can also be idiopathic, meaning that there is no clear cause for the inflammation.

Clinical Signs

Stomatitis can be extremely painful, but the symptoms can be difficult to recognize unless severe.

Signs include:

These signs are fairly vague and can all be associated with other types of dental disease. Your pet’s quality of life can be severely affected by mouth pain. It is very important to get your pet evaluated by a veterinarian if there is a concern.

Canine Stomatitis

Stomatitis in dogs is relatively uncommon. The most prevalent type of stomatitis seen in dogs is known as chronic ulcerative paradental stomatitis (CUPS). This syndrome most often causes inflammation along the membrane (mucosa) that lines the inside of the lip and cheeks. Another name for this inflammation is “kissing lesions”, because they appear where the teeth “kiss” or touch the mucosa.

The cause for CUPS is often idiopathic, but it is suspected that the most common cause is an immune response.

While any dog can be affected by CUPS, there are some breeds that are predisposed to the disease.

These include:

Feline Stomatitis

Stomatitis in cats is more common and is usually a chronic condition, meaning that it can be a problem for months to years. This is referred to as feline gingivostomatitis (FGS).

All cats are at risk for developing stomatitis, but there does appear to be a higher incidence in purebred cats such as:

Similarly to canine stomatitis, an immune-related cause is usually suspected in the majority of cats due to the presence of antibody secreting cells, called plasma cells, that are found when inflamed tissue is examined microscopically. A reaction to the plaque on the teeth which initiates this immune response is believed to be the cause of the majority of FGS.

It has been recognized that cats with a compromised immune system, such as those who are positive for feline immunodeficiency virus (FIV) or feline leukemia virus (FeLV), may have an increased risk of stomatitis. These cats are unable to fight off the progression of dental disease due to their weakened immune system.

Cats with uremia, a result of kidney disease causing a buildup of waste products in the blood, commonly suffer from oral inflammation. In addition, these cats have an increase of ammonia in their saliva, causing ulcerations and exacerbating inflammation.


Diagnosis of stomatitis can be difficult as the symptoms are common to many dental diseases. A veterinarian will need to get a full history on your pet and do a complete exam (both general and oral).

A sedated oral exam involves placing the animal under general anesthesia. While sedated, the veterinarian can examine the teeth, gums, and throat of the animal without causing pain or undue stress. The vet may also take samples of the inflamed tissue to help obtain a definitive diagnosis. This tissue can either be examined by the doctor themselves or sent to an outside lab for examination.

Blood work will also be run to identify any underlying disease that is contributing to the inflammation. Commonly, a complete blood count (CBC) and biochemistry panel will be conducted. Most clinics have the ability to run these simple tests in house and can have the results in a matter of minutes.

A decrease in white blood cells called neutropenia may be seen on the CBC, which is common for pets suffering from inflammation. However, test results are usually normal. The biochemistry panel may show increased kidney values or other increased metabolic values that point to an underlying disease process.

Once a diagnosis of stomatitis has been reached, the veterinarian will discuss the best options for treating your pet.


Treatment of stomatitis begins by treating any underlying disease that may be causing the inflammation. A full dental prophylaxis, or cleaning, is necessary to manage the oral disease while the underlying condition is being treated.


Pain medications are absolutely necessary to help keep an animal comfortable. Antibiotics may be needed if the veterinarian suspects a bacterial infection, though their effectiveness is limited. Anti-inflammatory medications such as steroids may provide symptomatic relief for a short time.

Cyclosporine, an immunosuppressive medication, has been used to successfully improve inflammation in approximately 75% of cats.

Dental Care

Owners will have to manage their pet’s dental care at home. This means brushing daily and feeding a hard, dry diet that is designed to prevent the accumulation of plaque. Mouth rinses may also be prescribed by your veterinarian to help remove plaque below the gumline.

Dedication to oral hygiene can help prevent progression of the disease. Close monitoring of your pet’s mouth is necessary to identify if inflammation is recurring. Frequent follow up with the veterinarian is also imperative, and usually scheduled every 3 to 6 months. A veterinary dentist may also be necessary to help manage your pet’s condition.

Tooth Extractions

Maintaining dental health for your pet at home can be difficult. Cats in particular are not known to be amenable to toothbrushing. This usually means a relapse of stomatitis, which may require tooth extraction. This treatment is particularly effective in animals with an intolerance to dental plaque. By eliminating the surface that the dental plaque adheres to, the inflammation may also be eliminated. Full tooth extractions may be warranted in animals with this sensitivity.

Removing all of your pet’s teeth can be a scary prospect, however, most animals thrive once they have had full mouth extractions. With the cause of the inflammation gone, the animal is no longer in pain.

Laser Therapy

While tooth extractions help most patients, up to 20% of animals do not positively respond to the procedure. CO2 laser therapy is the next option to remove inflamed tissue.

This laser emits a small beam of invisible light which is focused on a small area of tissue. As the tissues absorb the light, the water evaporates and injured tissue and bacteria are vaporized. This promotes tissue healing in the mucosa. Multiple rounds of laser therapy are needed to control the inflammation, but this process usually leads to resolution of the disease.


Prognosis in animals with stomatitis is usually good. If the cause of the inflammation is identified, treatment is frequently successful, especially in dogs. Cats may be more difficult to treat due to the chronic nature of the disease. This can be frustrating to owners and can cause poor quality of life for affected cats. Treatment can also be quite costly, which may be prohibitive to some owners.

With appropriate diagnosis and care, treatment of both canine and feline stomatitis can be successful, allowing your pet to live pain free.