Microbiologic evaluation of gallbladder bile of healthy dogs and dogs with iatrogenic hypercortisolism: a pilot study.

BACKGROUND: In people, hypercortisolism (HC) has been associated with acalculous cholecystitis and biliary dyskinesia, which may potentiate ascending biliary infections. In dogs, an association between HC and gallbladder disease recently has been documented, although the role of bacteria remains controversial. Furthermore, there is no information on the gallbladder bile microbial flora in healthy dogs.
OBJECTIVES: To investigate the microbial flora in gallbladder bile in healthy dogs, the relationship between iatrogenic hyperadrenocorticism and bactibilia and possible changes in biliary microbial flora after cortisol withdrawal in dogs. ANIMALS: Six control dogs and 6 dogs treated with hydrocortisone.
METHODS: Gallbladder bile obtained by percutaneous ultrasound-guided cholecystocentesis was cultured aerobically and anaerobically and examined cytologically before (d0), during (d28, d56, d84), and after (d28p, d56p, d84p) administration of hydrocortisone (8 mg/kg PO q12h).
RESULTS: In the control group, 2/42 bile cultures yielded bacterial growth (Enterococcus sp.; Escherichia coli on d0) and 1/42 bile smears had cytological evidence of bacteria (d28). In the HC group, 2/42 bile cultures yielded bacterial growth (Enterococcus sp. on d28; Bacillus sp. on d28p) and 3/42 bile smears had cytological evidence of bacteria (d84, d84, d28p). All dogs remained healthy throughout the study period (168d). CONCLUSIONS AND CLINICAL IMPORTANCE: Based on the results of conventional bacterial culture techniques, gallbladder bile of healthy dogs periodically may harbor bacteria, which do not appear to be clinically relevant. A 3-month period of iatrogenic HC was not associated with bactibilia. A higher prevalence of bactibilia may be detected with micromolecular techniques.