This damage alone may kill the animal (usually called acute fascioliasis) or may make it susceptible to black disease, a form of hepatitis. The liver is damaged during this migration. Occasionally a fluke may migrate through other organs or may infect the unborn foetus. The larvae then migrate to the animal’s liver before entering the bile ducts. These larvae form cysts on herbage and are eaten by cattle and sheep. Which invade the intermediate host, the snail Pseduoduccinea columella. To survive and reach the host snail, which must be within 24 to 30 hours as they have a short life span, the larvae need temperatures above 5☌ with the optimum temperature being 15☌ to 24☌.Īfter five to eight weeks and several larval stages later, depending on the temperature, minute tadpole-like larvae emerge from the snail. With favourable circumstances-water and moist conditions-the eggs hatch into larvae (miracidia) The eggs are then passed down the bile ducts and enter the intestine to eventually be excreted with Liver flukes mature and live in the bile ducts of the host where they lay large numbers of eggs. The adult flukes may also cause inflammation to and blockage of the bile ducts leading to jaundice and cirrhosis of the liver. Into the peritoneal cavity, which may result in sudden death. The damage done may be so severe as to cause a rupture of the liver capsule and haemorrhage From there they penetrate the liver where they mature and cause damage as they move around. How is Damage Caused?Īfter ingestion of infested pasture by a host animal, the young flukes penetrate the animal’s intestinal wall and enter the peritoneal cavity. If flukes are detected in livers at the abattoir, the livers are condemned as unsuitable for human consumption. Adult flukes are pale brown or greyish-brown in colour and when mature vary from 15 mm to 40 mm in length and up to 12 mm in width. A liver fluke burden can result in deterioration in wool quality, reduced meat and milk production and ill-thrift in young stock. Horses, deer and goats may also harbour liver fluke and humans too can be infected.Ī flat, leaf-like parasite, liver fluke has a complex life cycle. Liver fluke, Fasciola hepatica, would be financially devastating to the livestock industries if it became established in Western Australia, as eradication would be almost impossible.Īn economic model assessed the likely annual impact of liver fluke on Western Australian agriculture at $8m per year in 2000.įascioliasis is a disease caused by liver fluke in the liver and bile ducts of sheep and cattle. However, sheep are more susceptible to the disease than cattle.
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