Spontaneous Course of Biliary Sludge Over 12 Months in Dogs with Ultrasonographically Identified Biliary Sludge

Abstract

BackgroundBiliary sludge is associated with gallbladder (GB) dysmotility and mucus hypersecretion suggesting a link between biliary sludge and the formation of GB mucoceles (GBM). If biliary sludge progresses to GBM, treatment to reduce the production and progression of sludge is warranted.Hypothesis/ObjectivesThe objective of this study was to determine the course of biliary sludge in dogs.AnimalsSeventy‐seven healthy, client‐owned dogs ≥4 years of age screened for biliary sludge; 45 affected dogs identified.MethodsProspective, observational design. Serial ultrasound examinations were evaluated at 3, 6, 9, and 12 months to monitor degree of sludge based on proportion of GB filled with sludge (mild [0.01–24.4%], moderate [24.5–49.4%], moderate to severe [49.5–74.4%], severe [74.5–100%]), gravity dependency of sludge, and GB dimensions.ResultsAfter 1 year of follow‐up, the degree of sludge was mild (34%), moderate (47%), moderate to severe (13%), severe (3%), or absent (3%). There was no significant difference in median degree of sludge over 1 year (P = .36). There were no significant changes in the gravity dependency of sludge over 1 year. A subset of dogs, 24%, with initial gravity‐dependent sludge developed a combination of nondependent and dependent sludge. Dogs had resolved (2%), decreased (19%), static (40%), increased (29%), or recurrent (10%) sludge at the conclusion of the study.Conclusions and Clinical ImportanceBiliary sludge was prevalent, affected dogs remained asymptomatic, and it rarely resolves in healthy dogs over a period of 1 year. Some dogs developed nongravity‐dependent sludge within 1 year, which might indicate changes in consistency of sludge.

Clinical characteristics and histology of cholecystectomised dogs with nongravity‐dependent biliary sludge: 16 cases (2014‐2019)

“…Gravity‐dependent biliary sludge has been observed to progress to NDBS (DeMonaco et al . 2016) and it is possible that gall bladder dysmotility and cholecystitis are more important for the progression of gravity‐dependent biliary sludge to NDBS than cystic mucosal hyperplasia in dogs. Based on the literature search, similar progression from NDBS to GBM has not been reported although it has been speculated that the formation of NDBS precedes GBM formation (Tsukagoshi et al .…”

“…2014, DeMonaco et al . 2016). At the stage of disease reported in this study, in which a mixed pattern of anechoic bile and NDBS was present on ultrasonogram, the dogs could not be described to have GBM based on histological evidence.…”

Gall bladder mucoceles in Border terriers

“…Supersaturation of bile with cholesterol has been associated with impaired gallbladder motility in people and sludge formation in dogs and thus, may be a precursor to GBM formation. However, gall bladder sludge, while prevalent in older dogs, has not been shown to progress toward significant biliary disease over the course of a year and might not represent a risk factor in its own right. A recent study into the mechanisms of GBM formation identified a disproportionate increase in the gel‐forming mucin Muc5ac relative to Muc5b, defective mucin un‐packaging and altered levels of mucin‐interacting proteins as potential contributory factors .…”

Percutaneous ultrasound‐guided cholecystocentesis: complications and association of ultrasonographic findings with bile culture results

“…, DeMonaco et al . ). Signs commonly reported with septic cholecystitis and cholangitis/cholangiohepatitis are symmetric or asymmetric gall bladder wall thickening, dilated common bile duct, double‐layered wall, hyperechoic wall, hyperechoic gall bladder contents and choleliths (Hittmair et al .…”