liver fluke

US /ˈlɪv.ər ˌfluːk/
UK /ˈlɪv.ər ˌfluːk/
"liver fluke" picture
1.

a parasitic flatworm that infects the liver of various mammals, including humans, causing liver disease

:
The sheep was infected with liver fluke.
Eating raw or undercooked fish can lead to liver fluke infection in humans.