Liver fluke is a significant issue for production animals in the UK, particularly for sheep and cattle. The Liver Fluke parasite, Fasciola Hepatica, has become increasingly common and poses serious health and economic challenges for farmers. Successful treatment of Liver Fluke is dependent upon diagnosis, a range of wormers are effective, but their success depends on the age of the Liver Fluke.
What is Liver Fluke?
Liver Fluke, or Fasciola Hepatica, is a parasitic flatworm that feeds on blood and causes liver damage. It lives in the bile ducts of infected animals. Grazing cattle and sheep are especially vulnerable, but liver fluke can infect many mammals. If untreated, Liver Fluke can live in animals for years.
What Animals Can Get Liver Fluke?
All mammals can get Liver Fluke, but livestock grazing on “flukey-pasture” are at higher risk. This includes sheep, cattle, horses, pigs, goats, alpacas, and deer, as well as wild animals like wallabies, rabbits, and monkeys. Because Liver Fluke isn’t host-specific, managing pasture burdens through grazing isn’t effective. Wildlife can spread infection and resistant fluke strains from farm to farm.
Symptoms of Liver Fluke
Liver Fluke can be acute, sub-acute, or chronic, depending on how many fluke larvae are ingested and over what period. Symptoms of a Liver Fluke infection include:
- Anaemia
- Soft swelling under the jaw – sometimes known as ‘bottle jaw’
- Lethargy
- Suppressed appetite
- Poor growth
- Abdominal pain
- Sudden death in severe cases
The Impact of Liver Fluke on Production
Liver Fluke can reduce:
- Growth rates
- Milk yield
- Fertility
- Wool quality
Treatment
Treating Liver Fluke is different from other parasites. Farmers, vets, and animal health professionals must know if treatment is needed. Various wormers/drenches are effective, but their success depends on the age of the Liver Fluke. Some treatment targets immature Flukes, while others work on adults. Triclabendazole is effective but should be reserved for acute cases in sheep due to increasing resistance.
Lifecycle of Liver Fluke
Grazing animals ingest cysts (metacercariae) on herbage in a mud-snail habitat. These cysts release immature Fluke eggs in the small intestine, which then migrate to the liver and bile ducts to mature and lay eggs. The cycle takes about 6-8 weeks, with egg shedding starting 8-12 weeks after infection. Adult Fluke can live for years and produce over 20,000 eggs daily.
Environmental Conditions
Optimal conditions for Liver Fluke include temperatures above 10°C and lots of moisture. Eggs develop and hatch in mud-snail habitats, where they undergo multiple replication rounds before becoming infective cysts. Infection in snails takes about 5-6 weeks, but snails can remain infected during hibernation or droughts.
Managing Liver Fluke Risk
To mitigate Liver Fluke risk these farm management practices are recommended:
- Maintain good biosecurity
- Monitor regularly
- Use fluke drenches responsibly
- Know your pasture risk areas
- Practice strategic grazing
- Consult your farm vet regularly
Rumen Fluke
Rumen fluke are an under-studied parasite with debate around whether it causes disease/performance-loss, so simply detecting it does not necessarily mean the animals need treating. And if disease is seen with Rumen Fluke then it is caused at the prepatent stage, so no eggs would be seen then anyway. This parasite is not the focus of our test, but we will report if it is detected. If you do receive a positive result in the mast majority of cases you will not need to take any action. Speak to your vet/animal health advisor if you have concerns about animal performance.
Rumen Fluke is similar to Liver Fluke but lives in the rumen (first stomach chamber) of infected animals. It can only be diagnosed through Fluke FECs or post-mortem examination, as no antibody or antigen-based tests are available.
When is it best to use a Fluke Egg Count test?
As the fluke life cycle means egg shedding doesn’t occur for around 10 weeks after infection, the best times to use a Fluke Egg test tends to be later in the Autumn and over the Winter period. It is a waste of money and effort to sample young lambs or calves over the summer/early autumn period. Follow these tips on when and what to test:
- Test is suitable in adult stock classes for sheep and cattle.
- Only test lambs or calves > 6 months of age.
- Test in late autumn and winter to determine if any fluke picked up in summer.
- Tests in spring to early summer will help look out for contamination of eggs on snail habitats. Even if treated within the last 6 months they may have been reinfected or risk that treatment didn’t clear everything.
- Dairy cattle - during drying off period at any time of year (only time they can be treat).
How to Fluke Test with a FECPAK FEC Test Kit
Fluke testing with the FECPAK Test Kit is an easy three step process.
- Decide whether to take a mob or individual sample.
Mob Test
- A mob test combines multiple samples from individual animals to get an average egg count result for the mob.
- Mob tests are an economical way to build an overall picture of your mob’s average worm burden.
Individual Test
- An individual test can be used if you are interested in the results from a particular animal.
- For an accurate result of Fluke, sample at different times throughout the day or on successive days, to account for the irregular release of liver fluke eggs.
- Collect the Sample
Mob Collection
- SHEEP - 2 scoops from 25-35 different samples.
- CATTLE - 3 scoops from different parts of 15-25 samples
Individual Collection
- SHEEP - Collect whole sample.
- CATTLE - 3 x three-finger pinches from different areas of the sample
- Fill in Submission and send sample for testing
- Scan the QR code on the enclosed label to fill in the online submission form with sample details.
- Exclude air, seal the bag properly. Attach the QR label to the sample bag, place it into a leak-proof bag, and then into the postal box.
- Post the sample directly to our lab and await results. Track progress by logging into your account.
Tips to FEC Test like a Pro
- Samples should be as fresh as possible.
- Do not select samples based on their texture.
- Remove air from the sample and refrigerate immediately if unable to send straight away.
- Collect and send your sample earlier in the week to avoid being held over the weekend
By adopting regular FEC testing as part of their parasite management strategy, farmers can make informed decisions that enhance the health and productivity of their livestock. For more information and to purchase the FECPAK Test Kit, visit the FECPAK Shop.