Incidence and pathological study of Explanatum explanatum (Creplin, 1847) Fukui, 1929 in goats in Andhra Pradesh, India.

Amphistomiasis, caused by species of Paramphistomatidae is an economically important disease in ruminants. Explanatum explanatum is a very common amphistome in bile ducts and gall bladder of cattle and buffaloes worldwide where as in goats, it is exclusively found in Asian countries. Screening of livers from 100 sheep and 154 goats during slaughter at local slaughter houses from October, 2014 to April, 2015 in Andhra Pradesh (India) revealed presence of amphistomes in main bile ducts and gall bladder in three goats (1.9%) and were not observed in livers of sheep. Grossly, the affected livers were congested and the bile ducts were firm, thickened and occluded with amphistomes along with light yellowish foul smelling fluid. There were no apparent changes in gall bladder. Amphistomes were identified as E. explanatum by the standard staining technique using borax caramine. Microscopically, sections of liver revealed areas of haemarrhage, necrosis and infiltration of mononuclear cells in the parenchyma and surrounding the bile ducts. The wall of bile ducts revealed connective tissue proliferation with a characteristic mucosal plug of bile duct drawn into the acetabulum. There was hyperplasia of bile duct epithelium along with marked proliferation of mucosal glands and mononuclear cell infiltration. This paper appears to be the first report of E. explanatum in goats from Andhra Pradesh, India.