Effective Treatment Strategies to Control Parasitic Roundworms in Sheep

摘要

There are a variety of worm species that can cause disease in sheep. Anthelmintics (wormers) are one of the major control options available for the treatment of gastro-intestinal worms; however worms are developing resistance to some of these anthelmintics. Undertake a post drench efficacy check to determine whether the class of wormer is still effective or whether wormer resistance is present. Treat bought-in stock and animals that been grazed off farm with wormers from both the 4-AD and 3-ML classes of drugs or 5-SI class and where possible yard for at least 24-48 hours prior to turnout. See page 8 for a full description of wormer classes. Turn out quarantine treated stock onto dirty pastures to ensure that any resistant survivors form only a minor proportion of the total population. It is essential to conserve the efficacy of new and existing wormers through correct usage (see recommendations section at the end of this news sheet). Use parasitological and performance monitoring to gather data which will enable you to set performance targets for your lambs. Plan a strategic worming program with your veterinary practitioner/health advisor that will reduce unnecessary treatments. Avoid frequent drenching with anthelmintics by integration with grazing management. Consider reducing treatment frequency further by using targeted treatments or by only treating identified individuals within the flock. This news sheet focuses on chemical treatment strategies for controlling gastrointestinal worms in sheep. Moredun acknowledges that strategies involving grazing management, improved nutrition and genetic selection are very important but, due to limited space, will not be covered in this news sheet. Further information can be found on the Moredun websitewww .moredun .org .uk and the SCOPS website www .scops .org.uk