Infectious Diseases

BEVA offers guidance for anthelmintic resistance

By Marie Rosenthal MS

Anthelmintic resistance, the environmental impact of anthelmintic use, and the wider One Health implications and potential risks to human health, are serious concerns.

The British Equine Veterinary Association (BEVA) added new guidance to its ProtectMEtoo Toolkit to give practical guidance about detecting and managing anthelmintic resistance during its annual congress in Birmingham, England.

Developed by BEVA’s Anthelmintic Working Group, led by Nicky Housby-Skeggs, BVetMed, CertAVP(ESO), PFCert Vet Ed, MRCVS, the new anthelmintic resistance section of the toolkit provides practical, step-by-step guidance about monitoring for resistance, interpreting results and managing confirmed cases.

Identifying resistance early allows changes to parasite-control strategies that can protect horse health and welfare; slow the development and spread of further resistance and preserve the effectiveness of the anthelmintic treatments that remain available. A fecal egg count reduction test (FECRT) is the most reliable method for determining whether an anthelmintic is working effectively within a group of horses.

The new section of the toolkit explains how to conduct and interpret FECRTs and provides guidance about the steps to take if resistance is confirmed. Once resistance has been identified, parasite control should focus on reducing further resistance rather than simply switching from one wormer to another.

The ProtectMEtoo Toolkit provides practical guidance on improving pasture management, increasing monitoring and maintaining refugia—the population of parasites that remains unexposed to treatment—to help slow the development of further resistance.

Resistance does not need to be confirmed before improvements to parasite management are made. Effective parasite control should be based on targeted treatment, regular monitoring, effective pasture and stable hygiene, and appropriate grazing management, according to
Dr. Housby-Skeggs.

“Together, these measures can reduce selection pressure for resistance and help preserve the effectiveness of available anthelmintics for the future,” Dr. Housby-Skeggs said.

The new anthelmintic resistance section of the ProtectMEtoo Toolkit can be found online. MeV