Effect of sample collection methodology on nasal culture results in cats

Empiric antibiotic therapy is often employed to treat feline chronic rhinosinusitis (CRS), however, collection of samples for culture should result in improved antibiotic selection and development of less antibacterial resistance. This study evaluated the effect of sampling method on culture results in 44 cats and found that aerobic and anaerobic cultures were positive significantly more often from nasal flush samples than from tissue biopsy samples. Frequency of positive Mycoplasma species culture did not differ between the two sampling methodologies, although results were discordant in eight sample pairs. Mycoplasma species were cultured from flush samples only in three cats and from biopsy samples only in five cats. These results suggest that a nasal flush sample is adequate for determining the presence of bacterial organisms in feline nasal disease, however, failure to culture Mycoplasma species from a nasal flush must be interpreted with caution.