As we all know, we have had a lot of rain this summer which has left pastures wet and muddy. This has provided the perfect conditions for the mud snail, which is a key player in the life cycle of fluke.
Liver fluke, or Fasciola hepatica was largely a problem confined to the wetter western areas, but is now a growing problem on farms in the east and we see more cases confirmed in the Borders.
Farmers without previous experience of fluke may not be familiar with animal symptoms so can be caught out. It can present in a number of ways. Most dramatically it can cause sudden deaths particularly in weaned lambs. This occurs when a large number of immature fluke eaten off the pasture migrate through the liver causing acute damage. This is seen in the autumn and early winter.
More commonly however, fluke infection will present as weight loss and poor growth rates. This is due to the damage caused by adult fluke in the liver and is most often recognised in adult ewes and cows. A review of your approach to liver fluke should be carried out now: farms with previous experience of fluke are likely to have problems again this year while all other farms must consider whether treatment for fluke is required particularly if poor performance is seen in stock.
A quick and inexpensive way of checking for fluke is to send faecal samples from 10 cattle or sheep to your nearest SAC laboratory for a fluke egg count. Stock on the wettest pastures will be at most risk and so should be targeted for testing. The presence of eggs indicates the presence of adult fluke in the animal and the need to treat.
For producers selling prime stock, the abattoir can also be a useful source of information highlighting any liver damage due to fluke.
Prevention is better than cure so it may help to restrict stock access to particularly wet areas as these areas are likely to have a high population of mud snails and therefore be heavily contaminated by fluke. Bought in animals can also be a source of infection and a planned approach to bio-security and treatment should be in place. Several treatment options are available but it depends on the time of year as to which is most appropriate. Over treatment should be avoided. The best option would be to discuss treatment with your vet.
Alwyn Ll Jones