Using parasiticides in cattle without considering the active ingredients in those products presents dangers for an operation. Using different parasiticide active ingredients can extend the effectiveness of parasite control products and play a significant role in the management of healthier cattle.
Some common, yet misguided, management practices can lead to an operation unintentionally increasing resistance in parasites. One type of parasiticide — macrocyclic lactones — saw the first documented case of resistance more than two decades ago, and now Cooperia and Haemonchus parasites have been demonstrated as resistant to macrocyclic lactones in more than half of all operations examined. Of course parasites must be dealt with, but producers need to find a balance in their management practices.
There are three common active ingredient families, and it is important to understand how they work to control parasites.