Repetitive Cattle Deworming May Cause Drug Resistant Worms

From: CattleNetwork.com
April 21, 2010

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.

USDA NAHM's Beef Survey Reveals Declining Efficacy Of Popular Dewormers

CattleNetwork
December 7, 2009

Pour-on dewormers commonly used by beef producers simply are not working like they used to, according to new research data from the U.S. Department of Agriculture (USDA) National Animal Health Monitoring System (NAHMS) Beef 2007-2008 cow-calf survey.