by Dr Ruth Wonfor Knowledge Exchange Hub, IBERS
Liver fluke or Fasciola hepatica is a common parasite of livestock. Liver fluke infections cause ill health as well as a reduction in growth rates and reproductive performance in affected livestock. Over recent years it has been acknowledged that the presence of liver fluke in the UK has increased and that the periods of risk for infections have become longer, as well as more difficult to predict. An increasing prevalence of liver fluke in the UK has been attributed to climate change where the intermediate snail host can thrive in increasingly wetter and milder climates. Thus, this shift in climate has improved and expanded habitats for the mud snail. Scientific modelling has suggested that Wales will be one of the eU higher risk regions for fasciolosis in the future. Furthermore, flukicide resistance and confusion over various flukicide activities is leading to unsustainable control. The first step in effective control of liver fluke is to establish whether there is infection present on the farm. Use of flukicides and control strategies without a definite confirmation of parasites is a flawed strategy. Strict quarantine and treatment measures of all bought in animals will prevent the introduction of fluke onto the farm. veterinary advice should be sought to develop an effective quarantine and treatment procedure. Pasture management is seen as an essential control mechanism; host animals need access to wetland habitats which harbour mud snails for the liver fluke to complete their lifecycle. Current research at Liverpool University is working on developing on-farm liver fluke control plans through the use of mapping pasture for snail habitats and either removing or restricting stock’s access to these habitats. Liver fluke resistance to flukicide products, especially those containing triclabendazole is a serious problem. Any perceived drug failures should be investigated through a faecal egg count reduction test to ensure that the lack of efficacy was due to drug resistance, rather than misuse of drugs or younger parasites surviving the initial treatment. Treatment management practices require more information so that different drug activities are understood, improving the efficacy of liver fluke control. Treatment protocols should always be discussed with your vet before beginning and withdrawal periods adhered to. To combat growing liver fluke concerns research in the Barrett Centre for Helminth Control (BCHC) at iBerS, Aberystwyth University is working to develop both a pen-side diagnostic test to quickly and easily diagnose resistance on-farm, as well as potential new treatments for liver fluke from natural plant extracts. A further worry for the future may be the interaction between rumen fluke and liver fluke infections, due to both parasites utilising the same snail for their lifecycles. researchers in the BCHC at iBerS are looking to further understand the relationship between these parasites utilising a number of techniques, including on-farm mapping. in the coming year Farming Connect will be involved in several projects which involve liver fluke.