An Update on Feline Chronic Gingivostomatitis

Feline Chronic Gingivostomatitis (FCGS) is a severe immune mediated inflammatory disease of the oral mucosa in cats. Proliferative ulcerative lesions are frequently seen lateralized to the palatoglossal folds. Although it is frequently observed in daily practice, much doubt exists regarding cause and treatment.
This article’s goal is to review current literature about etiopathology and best treatment modalities for the disease.

In a first instance, the chronic nature of the disease is suggested due to high prevalence of lymphocytes and plasma cells in the affected oral tissue. Additionally, the predominance of T CD8+ (cytotoxic) cells compared to T CD4+ (helper) cells shows that there is a cellular immune mediated cytotoxic inflammatory response towards an antigenic stimulus, most likely a virus. Additionally, previous studies in cats with FCGS have shown a decreased CD4/CD8 ratio, which in human medicine has correlated to a dysfunctional immune response or even chronic inflammation, leading to believe that there is an exaggerated immune response in FCGS.

Several conditions and infectious agents have been linked to this disease. Feline Calicivurs (FCV), Feline Herpesvirus (FHV-1), feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are some of the most implicated agents. Out of all of them, it seems that FCV is the most frequently observed. Other factors, such as dental issues, environmental stress and hypersensitivities have also been implicated.

Regarding environmental factors, a recent study found that the prevalence of FCGS in multi-cat households was higher in comparison to single cat households. Furthermore, each additional cat in the household increases the likelihood of developing FCGS 70%.

An association between FCGS and periodontal disease has also been described. Cats that present with both have a higher probability of also presenting with inflammatory tooth resorption. Therefore, dental radiographs are extremely important in the diagnosis and evaluation of cats with FCGS, since treatment of diagnosed periodontal disease is an integral part of the treatment of FCGS.

Recently, a study also found an association between esophagitis and FCGS. In a controlled study involving 58 cats, 98% of animals with FCGS had signs of esophagitis. Anecdotally, 2 cats treated for FCGS showed resolution of esophagitis at follow-up. One of the cats had a relapse of FCGS and consequently presented worsening of esophagitis, despite specific treatment of the latter.

In terms of treatment, there are two well known modalities: medical and surgical. However, when isolated, medical treatment is not enough as a long-term option. Therefore, the standard of treatment is partial or complete dental extraction, with or without additional medical therapy. Regardless of modality, pain management is of upmost importance with opioids in association with gabapentin being the most frequent option.

Some studies suggest that partial or complete dental extraction is the treatment that has best long-term outcomes. However, evidence also shows that partial extraction should be first choice and only when there is no positive response in 1-4 months should a complete extraction be chosen.

Since FCGS is an immune mediated inflammatory disease, the basis of medical treatment is immunosuppression or modulation. Corticosteroids (namely prednisolone) has been used as short term to control inflammation (1mg/kg/day during 3 weeks). Due to adverse effects associated with long-term administration, it is only recommended for symptomatic treatment, and should be tapered. Interferons can interfere with viral replication. Studies suggest that they are just as effective as prednisolone. Cyclosporine, on the other hand, has shown that, when used isolated, it is effective in 50% of cats. When used alongside dental extraction, it also showed very promising results.

Finally, mesenchymal stem cells also have immunomodulatory effects. Their effect on cats with FCGS has been studied and has also shown promising results. Studies involving mesenchymal stem cells are underway to better understand their role with FCGS.

In conclusion, although the exact etiology of FCGS is still inconclusive, there seems to be an inadequate immune response that appears to be exacerbated by a viral infection. The first treatment option should be dental extraction and most animals need additional medical treatment. Pain management should never be forgotten, and promising treatment options seem to be in the horizon.

Lee DB, Verstraete FJM, Arzi B. An Update on Feline Chronic Gingivostomatitis. Vet Clin North Am Small Anim Pract. 2020 Sep;50(5):973-982. doi: 10.1016/j.cvsm.2020.04.002. Epub 2020 Apr 18. PMID: 32360016; PMCID: PMC7194110.