Microbiologic Evaluation of Gallbladder Bile of Healthy Dogs and Dogs with Iatrogenic Hypercortisolism: A Pilot Study

Abstract

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.

Cytological Findings of 140 Bile Samples from Dogs and Cats and Associated Clinical Pathological Data

“…Complications directly attributable to cholecystocentesis were low in this study, and comparable to previous reports,5, 16, 17 but nonetheless 2 dogs (<2% of all cases with available follow‐up information) suffered from iatrogenic bile peritonitis. However, necropsy findings suggested that bile peritonitis was not the predominant disease process in either case.…”

“…The majority of dogs with bactibilia in our study lacked cytological evidence of concurrent inflammation, raising the possibility of transient colonization rather than true infection. Transient, self‐limiting bactibilia can occur in clinically healthy dogs,5 but lack of concurrent inflammation in the bile or gallbladder wall despite bactibilia also occurs in clinically sick dogs 2, 7, 9. Although most of the animals had clinical signs of hepatobiliary disease, these could not be clearly attributed to gallbladder disease in cases from Group 2, as comorbidities were present in most cases.…”

“…Findings include presence of single and mixed bacteria in both canine and feline bile samples, with or without cytological evidence of inflammation 5, 6, 7, 8. Fungal organisms9 have rarely been documented in the bile of a dog, parasite eggs have been found in bile of a cat and of cows,10, 11 and a single case report documents the presence of atypical lymphocytes in gallbladder aspirates from a cat with lymphoma 12…”

Hepatic fungal infection in a young beagle with unrecognised hereditary cobalamin deficiency (Imerslund‐Gräsbeck syndrome)

“…Although immunosuppression from corticosteroids alone cannot be ruled out, it appears less likely as hepatobiliary infection has not been demonstrated in beagles following chronic iatrogenic hypercortisolism (Kook et al . ). Translocation of enteric microorganisms is plausible given that severe chronic cobalamin deficiency may impact on the rapidly proliferating intestinal epithelium (Arvanitakis ).…”

The Liver

“…915F&G). Although bile is generally sterile, studies indicate that clinically healthy dogs may occasionally yield positive bacterial cultures without clinical significance (Kook et al, 2010). Cholecystitis is an infrequent disease of dogs but more commonly in cats, which present with vomiting and anorexia and elevated concentrations of cholestatic enzymes [ALP and gammagluta myltransferase (GGT)].…”