A Chilling Thought About Horse Deworming Schedules

Like you I’ve read many conflicting horse deworming schedule reports. And it seems that for every horse deworming program based on a rotational drug wormer schedule there’s another one saying only use ivermectin or yet another one that claims the best wor
Author:
Publish date:

I’ve come to the conclusion that the first thing we all need to do when it comes to our horse deworming schedule decisions is “chill.”

EQ_deworm_250

Like you, I’ve read many conflicting horse deworming schedule reports. And it seems that for every horse deworming program based on a rotational drug wormer schedule, there’s another one saying only use ivermectin, or yet another one that claims the best worming schedule for horses is a “target program,” which means you should deworm only for the parasites your horse has.

If you go target, you must take a sample of the horse’s manure to the vet to have it analyzed or do it yourself—do you have a microscope in your barn?—and then choose the drug that matches the eggs seen in the sample. If you have the time, money and desire to do this, go for it. I don’t.

But I’m not all-ivermectin either, as some folks say, as I’m reading some reports about resistance there, too (of course it is! The drug has been in use a long time, meaning that a couple of super worms learn to avoid it, then produced more super worms and super-worm grandworms). So I’m going to rotate drugs, but I won’t use a horse deworming schedule based solely on the calendar either, one that says to deworm the horses every 60 or 90 days with a different drug. That’s because each individual drug has a slightly different “repeat” range for a horse deworming program, so you need to mark your calendar by that.

To learn more about deworming, download our FREE guide—Deworming Your Horse: How to find the best deworming schedule for you and your horse.

Ivermectin’s recommended repeat schedule is 6 to 8 weeks; moxidectin is 12 weeks. Most others are every 4 weeks. So, if you’re doing horse deworming every 60 days, and you’re using a lot of the 4-week drugs, your horse theoretically has a gap in his worming schedule, but I don’t over react about it. I think you should also need to factor in the season (low in winter; high in spring) and your own farm management (low 2 horses on 10 acres; high 5 horses on 1 acre).

My equine worming schedule rotates in at least one of the more-expensive broad-specrum horse deworming powerhouses—the ones that get bots and most everything else—and that means either ivermectin or moxidectin. Plus, at least twice a year, that paste dewormer tube should include praziquantel for tapeworms.

When it comes to deworming horses, my advice is to sit back and take a deep breath. If your horses are healthy and between the ages of 2 and 15, they are fairly well equipped to battle small parasite loads. They just need a little well-planned help.

Cynthia Foley

Editor-in-Chief, Horse Journal