In early April, Bovine Veterinarian ran an article titled “Detecting and preventing drug-resistant parasites,” based on an FDA publication outlining possible causes for the development of resistant parasites and potential management solutions.
Knowing drug resistance in parasites is a complex issue with no clear consensus among the experts, we asked for responses from veterinarians and parasitologists to the FDA’s conclusions and recommendations.
Soon after, we received a response from veterinary parasitologist Lou Gasbarre, PhD, in which he questioned several of the recommendations in the FDA publication, specifically as they apply to beef and dairy cattle. In response, FDA’s Center for Veterinary Medicine sent the following letter, further explaining the publication and its recommendations:
“FDA’s Center for Veterinary Medicine thanks Bovine Veterinarian for featuring our brochure, “Antiparasitic Resistance in Cattle and Small Ruminants in the United States: How to Detect It and What to Do About It,” in your article published online on April 10, 2013. We also thank Dr. Lou Gasbarre for his comments, published online on April 29, 2013, on both your article and our brochure.
We want to take this opportunity to expand on and clarify some issues raised by Dr. Gasbarre.
Dr. Gasbarre mentions that the brochure is an over-simplification of the complex issues surrounding antiparasitic resistance in the cattle industry. He further mentions that although FDA lumped small ruminants and cattle together in the brochure, the differences between the two industries require fundamentally different strategies to address antiparasitic resistance.
We agree with Dr. Gasbarre that because the U.S. cattle industry is complex and stratified, veterinarians and producers have to manage parasites differently at each step. However, we think the general concepts of managing antiparasitic resistance outlined in our brochure, such as preserving refugia, not treating the entire herd, avoiding under-dosing, and reducing stocking density, can be practically applied to the cattle industry.
We intended for the concepts and recommendations in the brochure to be high-level. By presenting information about antiparasitic resistance in an easy-to-read format, such as a brochure, we hope to reach more veterinarians. We also hope that veterinarians will use our brochure to educate their clients about the emerging problem of antiparasitic resistance.