Roundworm Resistance to Dewormers Assessed in Canada
Resistant Parascaris equorum on Thoroughbred and Standardbred farms to ivermectin and moxidectin was identified in Ontario, Canada.
Rolph de Gannes, an equine veterinarian practicing in Southern Ontario, Canada, had the impression that ivermectin was not removing the equine roundworm Parascaris equorum in foals and weanlings on a Thoroughbred farm. Because resistance of P