Safeguarding public and animal health

You are here: VLA Home Page | Research & Surveillance | Liver fluke

Liver fluke

What is liver fluke?

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

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

Clinical signs

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 salmonellosis.

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. It can occur throughout the year, particularly in southern regions.

Control

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.