Isolation and characterisation of bacteria from pyothorax (empyaemia) in cats

Samples from 19 cases of feline empyaemia were examined. All cases had no prior treatment and specimens were collected by thoracocentesis after preparation of the skin as for aseptic surgery. Of the 87 bacterial strains isolated, 70 (80.5%) were anaerobes and 17 (19.5%) were facultative anaerobes. Fourteen cases contained mixtures of anaerobes and facultative anaerobes, and five contained anaerobes only. Bacteroides was the most commonly isolated genus (42.5% of all isolates). Clostridium villosum (16.1%) was the most frequently isolated bacterial species followed by Peptostreptococcus anaerobius and Pasteurella multocida (each 12.6%). The most commonly isolated anaerobic species was Clostridium villosum sp.nov. (20% of anaerobic isolates and 16.1% of all isolates) and Pasteurella multocida was the most commonly isolated facultatively anaerobic species (64.7% of facultative isolates and 12.6% of all isolates).