Liver fluke

What is liver fluke?

It is an internal parasite that infects the liver and causes disease (fasciolosis) in grazing animals such as cattle, sheep, goats, llamas and other exotic farm species.

It has a life cycle that involves an intermediate snail host, which it also parasitizes.

Geographical location

Fasciolosis used to be more common in the wetter western half of the United Kingdom compared to Eastern regions. 

Also, disease was more commonly encountered during the autumn and early winter.

With greater movement of infected animals and the changing climatic conditions, fasciolosis is now common throughout the United Kingdom and can occur throughout the year.

How to recognise the disease

The clinical signs vary according to the species, and are caused by the feeding activities, and migration, of the parasite in the host’s liver.

The signs include:

  • weight loss
  • diarrhoea
  • lethargy
  • anaemia
  • and in the worst cases, death.

Fasciolosis can cause sub-clinical infection resulting in production loss, such as lower milk yields in dairy cows, and lower growth rates in beef cattle.

It also predisposes livestock to other diseases such as salmonella.

Reducing the impact of disease

Liver fluke infection can be controlled by dosing with a flukicide drench, at the correct time of year, depending on the forecast for disease. For example, you would dose in the autumn and winter if it has been a wet summer that favours the parasite’s life cycle.

Contacting AHVLA

There is no legal requirement for farmers to report this disease to Government veterinary authorities. AHVLA would be interested to hear of any suspected cases of liver fluke. Please contact your local AHVLA Investigation Centre to discuss with a Veterinary Investigation Officer (VIO).

Further information

Cattle disease leaflets for farmers

AHVLA’s Herdsure® Cattle Health Improvement Service offers a testing programme for leptospirosis along with liver fluke, BVD, Johne’s disease, IBR and neosporosis.

Page last modified: 28 June 2013