Microorganisms associated with incisional infections after gastrointestinal surgery in dogs and cats

To determine the rate of incisional infections after gastrointestinal surgery in dogs and cats and describe the aerobic bacteria isolated from these infections.

Retrospective study.

Client-owned dogs (n = 210) and cats (n = 66).

Records of dogs and cats that underwent gastrointestinal surgery at the Matthew J. Ryan Veterinary Hospital at the University of Pennsylvania were reviewed for surgical procedures, presence of an infection, bacterial species isolated, perioperative antimicrobials administered, and outcome.

The median duration of follow-up was 14 days (4-35). Incisional infections were recorded in 7% (20/276) of cases. Among those 20 cases, culture results were available in 12 of 20 cases. The most common bacterial isolate cultured was Escherichia coli. The most common perioperative antimicrobials administered to treat incisional infection were cefazolin and cefoxitin. Only two of the bacterial isolates were susceptible to these antimicrobials. Bacteria isolated from incisional infections were most often susceptible to chloramphenicol, imipenem, and gentamicin.

Bacterial isolates from incisional infections in this population consisted of native gastrointestinal flora, which was often resistant to the most commonly used perioperative antimicrobials.

Contamination at time of surgery is the most likely source of incisional infection after gastrointestinal surgery. This rate of infection justifies more rigorous intraoperative hygiene protocols and evaluation of the antimicrobials' susceptibility of causative bacteria to guide antimicrobial treatment.