Losses can arise from slaughterhouse liver condemnations, reduced appetite, lower weight gain and occasionally even sudden death in animals affected.
“Good pasture management will be really important this spring for controlling fluke,” says Kelly Foley, a veterinary advisor with Norbrook. “Keeping feed faces and other high-traffic areas as dry as possible by improving drainage, and keeping animals away from flooded areas by fencing off streams, for example, will help reduce their exposure to fluke.”
Dr Foley says it will also be important to make sure new additions to a flock do not bring triclabendazole-resistant fluke with them.
“You can ‘buy-in’ resistant fluke if you are not careful, so it is vital to manage newly acquired animals with that in mind. Make sure you follow a suitable quarantine process and that you target both internal and external parasites before introducing new sheep to the existing flock,” she adds.
Dr Foley says rotating flukicides according to the time of year, and using them at the correct dose, will help to slow the development of resistance.
“Under-dosing tends to promote resistance, so it is worth checking that your dosing gun is calibrated correctly and the weighing device is accurate, so each animal gets the correct dose. Over-dosing increases the risk of unwanted effects, and also wastes money.”
Since 2017 is looking like a high-risk year, particularly for sheep farmers in many areas of the UK, it may be necessary to treat more frequently and think carefully about the type of flukicide being used. Dr Foley suggests talking to a local veterinary surgeon or Suitably Qualified Person who will be able to give advice based on the specific needs of an individual flock, and be aware of new developments.
“The key is having a health plan that is tailored to the needs of each individual flock and which uses the right treatment at the right time,” says Dr Foley.
Norbrook has produced a ‘Best practice guide for fluke and worm control in sheep’ that includes practical advice for fluke control on farms. For your free guide go to www.norbrook.com/resources