Fascioloides magna “Giant Deer Fluke”. Different behavior and pathology in different hosts. Fascioloides magna “Giant Deer Fluke”. Deer and Elk (normal hosts)—Liver migration, then matures in thin-walled fibrous cysts connected with bile ducts. (Well tolerated; eggs shed in feces). .
Adults are elongate, up to an inch in length.
Characteristic structure is: their circumoral collar of spines arranged in two rows.
37 spines in E. revolutum.
Internal organs are distinct and easy to identify.
Collar of spines around oral sucker
Vitellaria Testes Mehlis’ gland Ovary
Parasite shows low host specificity throughout cycle
1. Adults occur in birds and mammals.
2. Eggs are released via the feces into an aquatic habitat.
3. Miracidia hatch, swim to snail, and penetrate.
4. Sporocysts and rediae occur within snail. Cercariae are released.
5. Cercariae penetrate (2nd intermediate hosts) and encyst as metacercariae.
6. Definitive host is infected by ingesting 2nd intermediate
host, metacercariae excyst in stomach, and adults mature
in small intestine.