Feline inflammatory oral diseases are complex and painful conditions frequently associated with the presence of pathogens typical for upper respiratory tract infections. Accurate detection of these agents is essential for guided treatment and monitoring therapeutic response. In this study, we evaluated an in-clinic PCR assay targeting Feline Calicivirus, Feline Herpesvirus, Mycoplasma felis, Chlamydia felis and Bordetella bronchiseptica in cats diagnosed with inflammatory oral diseases. Initially, we compared the sensitivity and reproducibility of the in-clinic system with results obtained from a licensed external laboratory. Subsequently, we performed pre-treatment and, when positive, follow-up post-treatment testing to assess infection dynamics. While PCR itself is an established method, the availability of reliable on-site diagnostics significantly reduced turnaround time compared to conventional laboratory submission. This facilitated earlier clinical decisions, timely therapeutic interventions, and more effective management of affected patients. Our findings support the use of in-clinic PCR as a practical and efficient diagnostic approach in daily veterinary practice.