Dental Corner: Feline gingivostomatitis: How to relieve the oral discomfort

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Feb 01, 2006


Daniel T. Carmichael, DVM, DAVDC
Feline gingivostomatitis is probably the most frustrating oral disease seen in veterinary practice. Cats with this chronic, painful inflammatory disease can be severely compromised, and medical treatment can cause adverse effects.


Figure 1A. Gingivostomatitis in a cat. The cat is missing some teeth, but gingivitis is evident at the maxillary fourth premolar (arrow).
Affected cats exhibit a variety of clinical signs including partial to complete anorexia (often avoiding the hard portions of the diet), ptyalism, halitosis, weight loss, abnormal swallowing, and oral pain. Physical examination results show gingivitis, stomatitis, and possibly palatitis, glossitis, cheilitis, pharyngitis, and mandibular lymphadenopathy. Oral inflammation is often extensive, and affected tissues are typically ulcerated, proliferative, and hyperemic (Figures 1A & 1B). When gingivostomatitis was first described, purebred cats were reported to be at an increased risk,1 but all breeds of cat have the potential to develop the disease, including domestic shorthaired cats. And cats can become affected at any age.


Figure 1B. A thorough examination of the caudal oral cavity is performed while the cat is anesthetized. Stomatitis is especially severe in the caudal pharyngeal area (arrows).
The good news is that most patients with feline gingivostomatitis can be cured or at least show marked improvement with treatment. But, unfortunately, some patients will require lifelong therapy.

ETIOLOGY

The oral lesions associated with feline gingivostomatitis are often mistaken for an oral infection; however, gingivostomatitis is not an infection but rather an inflammation. The inflammatory lesions associated with feline gingivostomatitis are thought to be the result of a highly reactive immune system. The specific antigen that the immune system is reacting to is not easily identified and is often unknown. The fact that most of these lesions will resolve when the teeth are removed suggests the involvement of an antigen that is intimately associated with the teeth (i.e. bacteria). However, because not all inflammation resolves when the teeth are removed, it must be conceded that multiple antigens may be involved. Other antigens that may have a role in triggering the oral inflammation associated with feline gingivostomatitis include viral, food, or environmental antigens. Autoimmunity may also be a component of the disease.

DIAGNOSIS

Differential diagnoses for oral inflammation in a cat include feline gingivostomatitis, periodontal disease, inflammation secondary to feline odontoclastic resorptive lesions (FORLs), certain viral diseases (infection with feline herpesvirus or feline calicivirus) that can cause oral inflammation and ulceration, eosinophilic granuloma, oral ulceration secondary to uremia, and neoplasia. A complete patient evaluation is paramount to making a correct diagnosis and embarking down a specific treatment path.

To begin this evaluation, perform a physical examination, a complete blood count and serum chemistry profile, and serologic testing for feline leukemia virus and feline immunodeficiency virus infections. Perform additional testing and imaging as indicated. The results of these tests in cats with feline gingivostomatitis are usually unremarkable except for oral lesions, mandibular lymphadenopathy, and hyperglobulinemia.


Figure 2. A common site from which to obtain a biopsy sample is lateral to the palatoglossal fold (A). If lip commissures are involved, obtain a sample of this area (B) as well.
Next, administer an inhalation anesthetic, and perform a dental prophylaxis. Perform a gross and radiographic examination of the oral cavity. Extract all teeth exhibiting FORLs and all teeth with advanced or end-stage periodontal disease. Also, remove any root fragments (best identified radiographically). Finally, obtain samples of the inflamed oral tissue by using a 4-mm skin biopsy punch at several locations of actively inflamed tissue, and submit them for histologic examination. A common site of inflammation is lateral to the palatoglossal folds (caudal stomatitis) (Figure 2).

Histologic examination results in cats with feline gingivostomatitis show plasmacytic stomatitis or lymphocytic-plasmacytic stomatitis. There may be concurrent neutrophilic inflammation or even a superficial bacterial component, but the predominant population of cells will be plasmacytes and lymphocytes.