Hepatic coccidiosis caused by Eimeria ninakohlyakimovae in a goat (Capra hircus) in Japan.

Coccidiosis caused by Eimeria spp. is a significant parasitic disease that primarily affects the gastrointestinal tract. Hepatic coccidiosis is extremely rare in goats, and the causative species has not previously been identified by molecular methods. We report a case of hepatic coccidiosis in a 32-month-old goat. Histopathological examination revealed bile duct hyperplasia and necrosis, and abundant coccidian developmental stages within the bile ducts. Similar stages were identified in the duodenal glands, gallbladder, and pancreatic ducts. Sequence and phylogenetic analyses targeting the 18S rRNA gene from liver tissue and purified oocysts identified Eimeria ninakohlyakimovae. This is the first report of genetically identified hepatic coccidiosis caused by E. ninakohlyakimovae in a goat, providing important insights into the pathogenesis of E. ninakohlyakimovae infection.