Test the Effectiveness of Your Dewormer

Test the Effectiveness of Your Dewormer

“How do I know if my dewormer is working?” That’s a million-dollar question according to Doug Ensley, DVM, technical marketing manager at Boehringer Ingelheim.

In order to test the effectiveness of your dewormer product, Dr. Ensley recommends that producers work with their veterinarian to perform fecal egg count reduction tests (FECRT).

FECRTs assess the effectiveness of products being used, and can help detect if you have parasite resistance in your herd. Begin by taking two sets of fecal samples from your herd:

Sample 1: At the time of treatment, or according to your veterinarian’s recommendation.
Sample 2: 14 to 28 days later (depending on your treatment dewormer), from the same animals.

“Do this test on 20 percent of your herd, or 20 animals, whichever is fewer,” Dr. Ensley said. “Then, count the reduction in egg counts. We want to see a 90 to 95 percent fecal-egg-production reduction.” Less than that would suggest a resistant population is present.

From there, your veterinarian can help you determine the predominant worm species present in your herd and the right dewormer to ensure your herd is protected.