Feline gingivostomatitis (FGS) is a chronic disease that presents with painful erosive lesions in the pharynx, buccal mucosa, tongue, and gingiva. Clinical signs can include oral pain, halitosis, dysphagia, anorexia, and weight loss. Currently prescribed therapies are variably successful and include combinations of antibiotic therapy, immunosuppressive drugs, interferon therapy, CO2 laser therapy, whole-mouth tooth extractions, and a variety of other therapies. Infections with feline calicivirus (FCV), feline herpesvirus 1 (FHV-1), and Bartonella species are common differential diagnoses. Bartonella henselae and B clarridgeiae are transmitted between cats by Ctenocephalides felis and so infection can be extremely common. Studies that have evaluated the relationship between FGS and Bartonella species are few and contradictory; most relied on serum antibody titers to identify active infections. A prospective study was conducted to determine whether Bartonella species antibodies in serum or Bartonella species DNA in blood were more prevalent in cats with FGS than in control cats from the same regions of the country. Prevalence rates of Bartonella species DNA, FHV-1 DNA, and FCV RNA in the palatal tissues of healthy cats were compared with those of cats with FGS to determine whether positive test results correlated with the presence of FGS. A total of 131 client-owned cats were enrolled in the study: 70 with FGS confirmed by previous histopathologic testing and 61 healthy control cats. Results indicated that prevalence rates for Bartonella species antibodies and DNA in the blood and the tissues did not differ between the 2 groups. These findings could indicate that Bartonella species infections are not associated with this syndrome, or that Bartonella species infections are a cause of FGS; however, a link was not made because of study design or the inherent problems associated with interpreting Bartonella species test results. FHV-1 DNA was also not significantly different between groups. Only FCV RNA was present in significantly more cats with FGS (40.5%) than control cats (0%), suggesting that FCV was associated with FGS in some of the cats.

Commentary: The results of this cross-sectional study indicated that cats with gingivostomatitis were not more likely than control cats to test positive for Bartonella species by enzyme-linked immunosorbent assay, Western blot, or polymerase chain reaction. These findings add to our understanding that cats can harbor Bartonella species without clinical signs of disease. A history of upper respiratory tract infection and calicivirus but not herpesvirus was statistically associated with FGS.

Association of Bartonella species, feline calicivirus, and feline herpesvirus 1 infection with gingivostomatitis in cats. Dowers KL, Hawley JR, Brewer MM, et al. J FEL MED SURG 12:314-321, 2010.