Take parasite resistance seriously

Farm Forum

As a breeder and owner of a new foal, you are looking to the future. You can imagine that foal growing and running in the field at the mare’s side. You look forward to a growing horse with countless hours of training and preparation ahead. You imagine competing and, even more, winning.

But can you imagine sickness or even death from something like parasites? Prior to the development of effective dewormers, horses of all ages often suffered and died from parasite infections. Unfortunately, years of improper deworming practices have resulted in a rise of parasite resistance and reduced efficacy in certain drug classes.

“It is critical that we take parasite resistance seriously and become better managers of our horses,” said Nathan Voris, DVM, Equine Technical Services, Zoetis. “If we don’t take the time to evaluate our deworming practices, then we will likely see health problems that haven’t occurred since our grandfathers’ time.”

Research has shown internal parasites are becoming resistant to current anthelmintics (dewormers). Taking steps to fight resistance and improve parasite management will help maintain peak performance in our horses, Dr. Voris explained.

“Because anthelmintic resistance is an inherited trait in parasites, horse owners must adjust their traditional deworming practices,” Dr. Voris said. “Otherwise, the currently available dewormers will become less effective. Greater parasite burdens will likely lead to serious health problems in the future with fewer effective options to combat parasites.”

The American Association of Equine Practitioners (AAEP) has recently published its parasite control guidelines. Rather than treating a group of horses exactly the same way, guidelines suggest treating animals as individuals. Zoetis has developed an Individualized Deworming (ID) Plan that can eliminate the guesswork, protect young horses from parasites and prepare them for a long, healthy life ahead.

The guidelines specify that horses less than 3 years old require specialized attention when it comes to parasite control. Because they are more susceptible to parasite infection and have an elevated risk for developing disease, properly scheduled deworming treatments during this phase is extremely important.

“The most problematic parasites in foals and young horses are roundworms, which are also called ascarids,” Voris said. “Left untreated, ascarids are a serious health threat that can cause severe, lasting health problems.”

The AAEP parasite control guidelines suggest ways to keep parasites in check and keep foals healthy and growing. Not following the recommended guidelines inevitably puts your foal at risk for stunted growth, colic or many other health problems. As always, discuss your foal’s health management and problems with your veterinarian.