Bile Culture, Antimicrobial Susceptibility, and Hepatobiliary Pathology in Dogs Undergoing Cholecystectomy for Gallbladder Mucocele

Abstract

Gallbladder mucocele is a major cause of biliary disease in dogs, particularly affecting elderly and small-breed populations. Background: This study retrospectively evaluated 65 dogs that underwent cholecystectomy at a referral hospital in Seoul, Korea, (2022–2025) to characterize clinical features, bile culture results, antimicrobial susceptibility, and histopathologic findings. Methods: Signalment, ASA grade, preoperative laboratory data, bile culture and susceptibility results, and postoperative outcomes were reviewed. Results: Bile culture was positive in 21.3% (13/61) of cases, most frequently isolating Escherichia coli 38.5% (5/13) and Enterococcus spp. 30.8% (4/13). Approximately 18% of isolates were multidrug- or extensively drug-resistant, showing reduced susceptibility to β-lactams but retained sensitivity to imipenem and florfenicol. Preoperative increases in liver enzyme activities and C-reactive protein were common. Histopathology revealed gallbladder mucosal hyperplasia 90.4% (47/52) and inflammation 61.5% (35/52), often accompanied by hepatic inflammation or fibrosis. Toy Poodles were significantly over-represented (35.4%; OR = 3.1, p < 0.001). Antibiotic matching was not significantly associated with complications or the length of hospital stay (LOS). Conclusions: Although the bile-culture positivity rate was modest, the frequent detection of multidrug-resistant (MDR) and extensively drug-resistant (XDR) organisms highlights the clinical value of culture-guided antibiotic therapy. Routine bile culture with susceptibility testing, concurrent liver biopsy, and careful perioperative management may improve diagnostic accuracy and outcomes in canine gallbladder disease.