Antimicrobial prophylaxis in addition to premedication in gastrointestinal surgery

The aim of this study was to evaluate three combinations of antibiotics applied perorally prior to laparotomy and gastrointestinal surgery and to select the most favorable combination. Research was performed on 24 female and male dogs divided into four groups. Following abdominal wall incision the caecum was compressed manually and 5 mL of saline solution was injected into it. Five mL of caecum contents was aspirated in a sterile syringe and only 0.1 mL was incubated into blood agar and homogenous agar. Bacterial colonies were counted and determined. Prior to surgery the control group (n=6) received no antibiotics. The group which received the combination of gentamicin and clindamycin (n=6) achieved the best reduction of E. coli whereas Enterococcus faecals was 100% destroyed. The group which received amoxicillin with clavulanic acid and metronidazole (n=6) acquired a reduction of bacteria Enterococcus faecalis, which could be sufficient for prophylaxis. The combination of gentamicin and erythromycin (n=6) failed to accomplish a reduction of the number of bacteria.