Metorchis lives in the bile ducts of carnivores. This photo is a section through bile duct, with the epithelial layer in the middle and left of the photo, liver tissue to the bottomright, and the lumen of the bile duct on the top. A section through an adult worm (note the numerous eggs) is present in the lumen. The epithelium below the parasite seems intact, but above the parasite the epithelium has been abraded and the normal villar structure is absent. At higher magnification, inflammatory cells would be seen, and it is likely that the host is laying down a layer of connective tissue to prevent further damage. Severe infections can damage the function of the biliary system.