Epidemiology and control of parasites in northern temperate regions.

The serious and widespread problem of drug resistance has forced a re-thinking of basic philosophy regarding control of equine parasites. It has illustrated the dangers of total reliance on chemical control and stimulated the use of alternate strategies. Two new approaches are described. Prophylactic treatments in the spring and summer provide effective strongyle and colic control with less selection pressure for drug resistance. A nonchemical approach of pasture cleaning twice a week offers the same advantages with the added bonus of a 50 per cent increase in grazing area.