3 October 2012

3 minute read

Europe

Liver fluke costs the beef and sheep industry millions each year, with the vast majority of this loss being suffered by producers. Food Standards Agency records show more than 510,000 cattle livers, some 22%, were excluded from the human food chain in 2011 as a result of fluke infection. This represents an annual loss of over £1.7 million to the meat trade and similar losses might be expected in the sheep sector.

Although substantial, this is dwarfed by the estimated £25 to £30 cost to the farm of each case of liver fluke in cattle resulting from lower growth rates, lower feed conversion efficiencies and higher levels of mortality. These losses add up to some £15.3 million a year nationally, although recent work had suggested it could be significantly higher.

This year, the risk of liver fluke infections is high across all farms, including those with no previous history of fluke problems, as the wet summer weather is likely to have increased mud snail numbers dramatically and hence the liver fluke challenge on pasture. Liver fluke infections can be detected by screening stock for the presence of fluke eggs in the dung or via blood testing. Abattoir feedback on rejected livers is also an important source of information.

In the autumn, where there is a risk of acute liver fluke disease, triclabendazole (TCBZ) is the drug of choice for sheep and cattle, unless it has been established that there are resistant liver fluke on the farm. In this case get advice on suitable alternatives.

Cattle rarely show signs of acute fluke disease, therefore unless acute disease is suspected or diagnosed, a flukicide with activity against late immature/adult fluke stages (closantel, clorsulon, nitroxynil) may be selected, especially for treatments given in the late autumn/winter months. This should also help reduce the likelihood of resistance developing to triclabendazole.

Be aware of the possibility of re-infection if animals are put back on high risk grazing areas. Use management tactics such as moving stock to low risk fields, fencing off identified risk areas, or housing stock. If animals remain in these areas, then monitoring for infection is essential. Quarantine treatments for in-coming sheep and cattle are also likely to be needed due to the high risk of fluke infection this year.

Make sure you dose correctly, do not over or under-dose. Be prepared to split groups if there is significant variation in the weight of animals in the group. Don’t rely on chemical treatment alone – management tactics are an essential part of liver fluke control.

It is important to seek veterinary advice on product selection and timing, preferably as part of a regular testing and treatment protocol set down in the herd health plan.