Western
Meeting of Poultry
Clinicians and Pathologists
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Clinicians and Pathologists
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Cholangiohepatitis in Broiler Chicks B. Brandstaedter Agriculture Canada
Since early 1993, flocks of broiler chickens with relatively high condemnation rates for cholangiohepatitis are being seen at a poultry processing plant in Manitoba. Between February 1993 and July of that year, flocks from 8 different producers were affected. Only two of these producers had more than one flock showing the condition and only with one producer did the condition carry on through three production cycles. After that only occasional cases were seen with lesser degrees of severity of lesions. In June and September of this year, two cases were seen from producers whose flocks were not originally affected in 1993. The condition appeared to be more chronic with extensive peritonitis and liver necrosis. As the flocks were concurrently affected with ascites, this may be contributing to the severity of lesions seen. Birds with cholangiohepatitis characteristically have opaque and thickened gallbladders. The bile may be yellowish, opaque or even inspissated. The livers show varying degrees of involvement, but are usually enlarged and firm with evenly distributed necrotic lesions. Bile ducts are enlarged and can contain inspissated bile. In severe cases the gallbladder or a bile duct rupture, causing a fulminating peritonitis. Often the right lobe of the liver is more severely affected than the left. In well advanced cases we might even find it totally destroyed. An explanation lies in the fact that the gallbladder only collects bile from the right lobe whereas the bile duct of the left lobe drains directly into the duodenum, which makes it less likely for the biliary tree to become obstructed to the point where trapped bile causes the degenerative changes in the hepatic cells. In the cases we had examined and from the references found, typically Clostridium perfringens can be cultured from gallbladders and livers. It is not clear as to whether C. perfringens is the causative agent of cholangiohepatitis, or only a secondary invader. Attempts to demonstrate a connection with necrotic enteritis, which also involves C. perfringens, have not been successful. Other suspected connections are previous exposure to coccidiosis, mycotoxins or inclusion body hepatitis. Dr. Riddell of the WCVM indicated the condition may be controlled by adding Bacitracin in the feed at 100gm/tonne. This and the recommendation to thoroughly clean the feeder system appeared to clear up the condition in the barns involved in the cases we saw in 1993. I would like to thank Dr. Grant Spearman, Veterinary Pathologist with the Manitoba Agriculture Veterinary Services Branch, and his staff for the diagnostic work performed. |
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