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Rotating Dewormer Classes

By Sharon Biggs | May-06

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Rotating Classes

All dewormers are not alike. Each dewormer has an active ingredient (chemical) to control parasites in your horse. These chemicals fall into one of three different “classes,” and each controls different parasite species. When rotating dewormers, you need to rotate classes, not just the brand name or the chemicals within each class, otherwise certain parasite species may continue to flourish in your horse despite your best efforts.

Below is a chart of the three classes and the chemicals in each. For information on the various parasites each chemical controls, talk to your veterinarian and refer to dewormer product labels. Because they are considered drugs, equine dewormers—and their label claims—are highly regulated by the Food and Drug Administration.

Class Chemicals
Macrocyclic lactone ivermectin
Pyrimidine pyrantel tartrate
pyrantel pamoate
Benzimidazole oxibendazole
Additionally, praziquantel for the control of tapeworms in horses is now available in some dewormers.

Download the full dewormer chemical classes chart >>

Back to Managing Your Deworming Program >>

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Pony Princess    Horsetown, UT

2/3/2012 9:05:10 AM

Great info

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