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, 2009. 277-279.• http://www.cdfound.to.it/html/dicro.htm• http://www.dpd.cdc.gov/dpdx/HTML/

Dicrocoeliasis.htm• http://en.wikipedia.org/wiki/Dicrocoelium_dendriticum• http://www.fusabil.org/pdf/pdf_FUSABIL_438.pdf• http://www.nr.gov.nl.ca/agric/animal_diseases/

domestic/pdf/dicro.pdf