Spontaneous cholelithiasis in sheep: prevalence survey and analysis of gallstones and bile

In an abattoir survey of the consecutive series of 206 sheep at a local slaughterhouse, gallstones (concretions with a diameter equal to or greater than 1 mm) were found in the gall bladder of 24 animals. There were stones in 19 out of 146 adult sheep and in 5 out of 60 lambs, with the higher frequency in the male sex in both groups. Qualitative analysis of the stones showed that all of them were pigment (bilirubin) stones. There was no statistically significant difference (paired t test, P greater than 0.05) between the amounts of biliary cholesterol, phospholipids, bile acids and total and indirect bilirubin in 12 sheep with gallstones and 12 control sheep without gallstones, paired for age, sex and day of slaughter.