Dicrocoelium dendriticum By: Steph Covey and Ashley Zawacki

Background Information This is a trematode (fluke) It primarily affects sheep and other ruminants It has an indirect life cycle Common name – Lancet fluke – Small liver fluke 6 mm – 10 mm full grown

Geographic Location Found Worldwide Frequently present in: – Northern Asia – Europe (especially in Italy) – North America – Northern Africa

Host Definitive Host: – Sheep, cattle, pigs, goats, rabbits, members of the deer family – Rarely humans Intermediate Hosts – Snails – Ants

Pathogenesis Usually infections are light and asymptomatic Can become more serious and result in cirrhosis and distended bile ducts – Decreased liver function – Anemia – Edema – Weight loss – Sometimes can result in death

Pathogenesis cont. “Brainworms” in ant – Alter ant’s behavior – Colder temperatures vs. warmer temperatures Parasite influences the intermediate host to behave in a manner that increases the probability of passage to the definitive host

Diagnosis Microscopic detection of eggs in stool samples FALSE INFECTIONS!!!!!!!!! – Common in humans who have ingested raw infected animal liver Bile fluid containing eggs is actually a more accurate diagnosis than a fecal sample After animal is slaughtered, can be diagnosed by finding liver flukes in bile ducts or liver ELISA

Treatment Praziquantel – treatment of choice – Very expensive and not necessarily economically feasible Benzimidazoles

Control Difficult to control! – Ants and snails are too hard to control in pasture Keep cattle from grazing at night and in early morning when temperatures are cooler (also known as husbandry practices) Eggs can survive freezing Practice pasture rotation Deworm regularly

Sources Roberts, Larry S. "Foundations of Parasitology." New York: The McGraw-Hill Company, m m ic/pdf/dicro.pdf