Incredible video shows all the stages of the liver fluke lifecycle


Things to do at housing

Steps you should be taking now to protect your herd

Beef

  • Check if youngstock needs worming for gut worms at housing using faecal egg counts (FECs). If infection risk is high, use a product that contains a macrocyclic lactone (ML) to kill off inhibited Ostertagia worms to reduce the risk of Type ll ostertagiosis later in the winter. Adult cattle should not require any treatment for gut worms.
  • There is no natural immunity to liver fluke, so all ages of stock must be assessed for treatment where there is a history, or risk of infection. Check fluke forecasts and abattoir returns to monitor presence of fluke
  • Blood test a group of first season grazing calves (as sentinels) two weeks after housing to check whether they have been in contact with liver fluke in the summer

Dairy

  • Check if youngstock needs worming for gut worms at housing using faecal egg counts (FECs). If infection risk is high, use a product that contains macrocyclic lactone (ML) to kill off inhibited Ostertagia worms to reduce the risk of Type ll ostertagiosis later in the winter. Adult cattle should not require any treatment for gut worms
  • Take a bulk milk sample to test if the milking herd has been exposed to liver fluke.
  • There is no natural immunity to liver fluke, so all ages of stock must be assessed for treatment where there is a history, or risk of infection. Check fluke forecasts and use abattoir returns to monitor presence of fluke

Resources

Vet, academic or researcher?

Take a look in Resources for more detailed information on all topics.

26th November 2021

COWS has uploaded a video of the different stages of the liver fluke parasite from egg-laying adult to egg-laying adult.

Moving images prove to be much more powerful than any Life Cycle drawn on a piece of paper, and really hit home how fascinating and potentially pervasive these parasites are.

See the video here

This piece of work has taken many years and has been produced by parasitologist Dr Clive Bennett, working with cameraman David Barlow. The live liver fluke stages were provided by Ridgeway Research Ltd.

Fasciola adults are flat worms that live in the bile ducts of cattle and sheep. To hold their position and move they use suckers and spines. Eggs are produced in their millions passing through the gut and onto pasture in faeces to reach water.

Miracidia develop in the eggs to hatch after two weeks. The miracidia are attracted to mud snails that live and breed on the pastureland to infect young snails. The miracidia attach and shed their outer layer. Once inside, miracidia become sporocysts. One sporocyst can produce up to 4000 cercariae. The cercariae emerge from the snails and swim vigorously until they find a surface to which they can attach forming a cyst and shedding their tail.

Cysts on pasture await ingestion by a mammalian host. Digestion in the gut releases a metacercarial cyst and activates the juvenile fluke inside to excyst!

The juvenile uses its suckers and spine to work its way through the gut and liver to the bile duct and complete the life cycle releasing more eggs…