Over the past ten years, light has been brought to the growing problem of antibiotic resistance in humans and animals. Doctors and veterinarians are working together diligently to use these medications more judiciously so that future generations have access to drugs that are effective. What is surprising to me is that not nearly as much publicity has been given to the growing problem of parasiticide resistance in livestock.
For similar reasons to antibiotics, parasiticides are becoming less and less effective in our livestock animals. Access to these products over-the-counter has allowed people to treat their animals on their own. Regimens typically include treating a whole herd several times a year without a truly proven need. This leads to poor control and the development of resistance. Parasites like Haemonchus contortus are running rampant and causing huge production losses for farmers across the country.
I remember a lecture during third-year about antihelminthics and the professor saying that within the next 10 years our products could be obsolete. We are already in need of new and improved products that are effective against resistant species of parasites, but research and development have not progressed as quickly as resistance. This isn’t just a problem within the United States either. It exists all over the world.
But what is the solution? For now, farmers should work diligently with their veterinarians to develop a parasite program that is targeted to their specific needs. Medication should not be administered without proven need and animals should be regularly tested. Dosing and drug selection need to be appropriate for the animal and parasites being treated. Those are just the first steps to help prevent the evolution of resistant parasites. Hopefully, with new research and products, we will get this problem under control.