Prevalence of gallbladder sludge and associated abnormalities in cats undergoing abdominal ultrasound

The significance of gallbladder sludge in cats remains largely unknown and has been speculated to be a pathologic finding in cats. The objectives of this retrospective, observational study were to determine the prevalence of gallbladder sludge in the population of cats presenting for abdominal ultrasound; to describe clinical signs, laboratory findings and certain abdominal ultrasound abnormalities; and to compare these findings to cats without gallbladder sludge. One hundred and ninety-two cats were included. Medical records were searched for cats with an abdominal ultrasound performed between October 2014-2015. Signalment, clinical signs, complete blood count, biochemical findings, presence or absence of gallbladder sludge, and hepatobiliary and pancreatic ultrasound findings were recorded. Gallbladder sludge was present in 44% of cats that underwent an abdominal ultrasound. There was no significant difference in age, sex, presenting clinical signs or clinicopathologic variables between the two groups. Gallbladder wall thickening significantly increased the odds of detecting gallbladder sludge (OR-3.7 95% CI 1.4 - 10.0). Gallbladder sludge was not associated with other ultrasonographic abnormalities of the liver, gallbladder, bile duct or pancreas. Gallbladder sludge is common in cats undergoing abdominal ultrasound and appears to be a non-specific finding. The clinical significance of concurrent gallbladder sludge and gallbladder wall thickening present on ultrasound in cats remains to be determined.