Repetitive Cattle Deworming May Cause Drug Resistant Worms

– Amy Radunz, Beef Cattle Extension Specialist, UW-Madison

Dewormers have provided effective parasite control, which has resulted in returns to farmers between $20 to $200/hd. The cost of these products is reasonable when compared to potential productions gains provided. Sheep and goat farmers have long battled with drug resistant worms, however until recently there has not been evidence of this is occurring in beef cattle. In fact, some of the first evidence of worm resistance in cattle was found in Wisconsin in 2002, when a backgrounder, who acquired calves from the Southeast, experience lower than expected weight gain during the fall.

According to Dr. Shulaw, Extension Veternarian at Ohio State University, “Unlike sheep and goats, cattle tend to develop a much stronger immune response to gastronintestinal parasites after a season of grazing exposure.” However, research Continue reading