Many veterinarians are encouraging their clients to rethink their deworming protocol, as we now know that too-frequent anthelmintic treatment can lead to drug-resistant parasites. But French scientists have raised another important concern: How do the antiparasitic drugs impact the environment?

In a preliminary study, researchers investigated parasite control practices at equestrian centers neighboring a natural reserve and then looked at how insect populations in the reserve were faring. The team presented their work at the 2014 French Equine Research Day held March 18 in Paris.

Specifically, they looked at feces-consuming beetles in spring and summer over a two-year period. They compared beetles in areas close to horse-riding trails to those in areas closed off to horses. The study was coordinated by Anna Echassoux, PhD, vice coordinator of the Biosphere Reserve of Fontainebleau and Gâtinais, and led by Julien Gasparini, researcher in ecology at Pierre et Marie Curie University in Paris. Brigitte Enriquez, researcher in pharmacotoxicology at National Veterinary school of Alfort, and Jean-Pierre Lumaret and Nassera Kadiri, researchers in entomology at Montpellier University, also contributed to the study.

Echassoux and her team found that in May and June, the dung-eating bugs in the horse-riding areas actually fared better than those without access to horse droppings. However, the opposite was true in July, when the horse-area beetles were fewer in number and had shorter legs than the beetles in non-horse areas.

This could be related to seasonal deworming practices, Gasparini said. Previous studies with sheep and cattle feces have shown t