North American Veterinary Licensing Examination (NAVLE) Practice Test

The most likely underlying organism related to the situation described is Pasteurella multocida. This bacterium is commonly associated with cat bite wounds and fights, where superficial puncture wounds can introduce bacteria from the oral cavity of one cat into the tissues of the other. Pasteurella multocida is known for causing rapid-onset infections characterized by swelling, pain, and sometimes cellulitis or deeper tissue infections following such injuries.

Feline oral flora predominantly contains this organism, and the bite itself causes tissue damage that allows Pasteurella multocida to infect the wound. The rapid development of symptoms post-injury aligns with the virulence of Pasteurella.

In contrast, while other organisms like Streptococcus equi, Clostridium perfringens, and Escherichia coli can cause infections, they are less commonly associated with feline bite wounds. Streptococcus equi is primarily linked to equine diseases, Clostridium perfringens is often tied to more severe anaerobic infections, and Escherichia coli is typically encountered in urethral or gastrointestinal infections rather than in bite-related soft tissue infections in cats. Therefore, the presence of painful swelling following a cat fight strongly points to Pasteurella multoc