HOW TO OUTSMART CATTLE WORMS

You've heard the saying, less is more. You just didn't know that it's true for your deworming program.

- Gene Johnston

When deworming cattle, the goal is to outsmart the worms, says Dan Cummings, a veterinarian and cattle deworming expert for Boehringer Ingelheim. Like any other organisms, parasites can adapt and become resistant to available dewormer drugs. A university survey in Georgia found that 11 out of 12 cattle farms had resistant worms, he says.

Resistance develops when a parasite management program leaves surviving worms behind after treatment. They become a challenge to control in following seasons. Poor management practices and product selection can speed up resistance development. For instance, repeated use of the same class of dewormer at incorrect dosages can lead to more resistance.

One helpful practice is to rotate the class of dewormer used. The two major classes are macrocyclic lactones (ivermectin) and benzimidazole (oral drench, also called white dewormers). Resistance to one product within a class could mean resistance to all dewormers in that class.