Feline chronic gingivostomatitis (FCGS) is a severe, painful inflammatory disease affecting the oral cavity of cats. Although the exact cause of FCGS remains unclear, bacteria are suspected to play a significant role in the disease’s pathogenesis. Several studies have investigated the microbial load of the oral cavity of cats suffering from FCGS, shedding light on the genetic and metabolic pathways that may lead to is disease.

In healthy cats, several physical and immune defense mechanisms, including the mucociliary apparatus, alveolar macrophages, and a tightly regulated immune system, work together to maintain the sterility of the lower airways. However, disruptions to these defenses, especially in immunocompromised cats, can lead to bacterial aspiration and increase the risk of respiratory infections. Studies of healthy feline respiratory tracts have identified a diverse, low-biomass microbiota dominated. The proximity of the oral cavity to the lower respiratory tract has suggested a potential continuity between the oral and lung microbiomes. This connection may be a contributing factor in the association between inflammatory diseases, such as FCGS, and respiratory conditions. The aim of this study was to investigate the interaction of the oral microbiome in cats with FCGS with the respiratory microbiome. Twenty-two client-owned cats with clinical signs of FCGS were included in this study. All cats underwent both clinical and oral cavity examination. After anesthesia administration a swab sample from the oral cavity was taken for microbiological examination. Prior to major surgery, each cat underwent tracheobronchoscopy, during which material was obtained with cytology brush for microbiological examination. The oral and respiratory samples were investigated for co-existence of bacteria Escherichia coli, Pseudomonas aeruginosa, Enterobacter aerogenes, Pasteurella multocida and Tannerella forsythia.

According to our preliminary results, Enterobacter aerogenes, Pasteurella multocida and Tannerella forsythia.appear to be present in both the respiratory tract and the oral cavity. The interaction between the oral and respiratory microbiome in cats provides critical information on the relationship between FCGS and respiratory diseases. While the etiology of FCGS is not fully specified, it is likely that bacteria may play a role in its evolution. The similarities of the oral and respiratory microbiota, combined with impaired immune defenses, highlights a possible link between the oral cavity microbiome and the respiratory microbiome in cats with FCGS. Further research regarding the microbial environment of both the oral cavity and respiratory tract will be necessary to understand the full extent of these interactions and to improve treatment strategies for cats with FCGS and other inflammatory diseases of the oral cavity.