Recommended worming protocols for horses of all ages have changed in the last few years, over-frequent use is very common. Young horses require particular attention as they are more susceptible to parasite infection and more at risk for developing disease.
Worming mares with a macrocyclic lactone such as moxidectin just prior to foaling prevents transmission of intestinal threadworm to the foal via her milk. Subsequently the foal’s first worming treatment is not needed until two-three months of age. Treatment should be repeated about every 3 months including one just before weaning. Recently weaned foals should be turned out onto the ‘cleanest’ pastures with lowest parasite burdens.A benzimidazole drug or pyrantel should be considered for these early treatments as resistance against the macrocyclic lactones has been seen in large roundworm. Encysted small redworm and tapeworm should be targeted at the end of the year, so a combined moxidectin and praziquantel dose for foals (over 6.5 months) is ideal. Accurate assessment of weight is essential to avoid under dosing. Good pasture management techniques benefits all age groups.Resistance is common in this age group. The only way to identify whether this is an issue on your yard is by performing faecal egg count reduction tests (FECRTs), which assess the efficacy of the worming treatment you have used. Ask your veterinary surgeon for further information.Zoetis IrelandTel: +353 1 2569800