I could myself very lucky that Dorado has always been very agreeable to deworming—the most objection he ever gives is simple flipped lip and a post-deworming stare-down, as if to say, "Look what you made me do…look at my lip!" But last night, as I wiped globs of dewormer off my jacket and pants before picking some more up off the barn aisle floor and stuffing it back in his mouth, I remembered that our aging horses—even the seemingly cooperative ones like my dear Thoroughbred—have had a lifetime to learn how to avoid deworming.

Dorado is cooperative when it comes to deworming...usually.

Photo: Kristen Janicki

Even if they object to it, there's a reason we deworm our horses (although they don't tend to listen and understand if we try to explain it to them). But with the deworming tides changing, some owners might be rethinking their deworming strategies for their equine seniors.

I was raised on rotation deworming. The protocol was actually very easy for me to follow: each year I asked Santa for the deworming bundle that many horse supply stores sell and was thrilled to find it under the tree on Christmas morning. Then, every other month, I'd grab the appropriate anthelmintic, bribe Dorado with a few treats, wiggle the tube between his tightly sealed lips, and my horse was protected from worms for the foreseeable future.

Unfortunately, we're now facing problems with anthelmintic resistant parasites. Many veterinarians and researchers are now suggesting fecal egg count tests and fecal egg count reduction tests to identify which horses need deworming and which product should be used to effectively fight the worms present in each animal. Some owners have happily switched over to this method while others remain resistant to change.

With all the options, recommendations, and research out there, it might not be easy to make a decision on how to best manage parasites without asking a veterinarian—it wasn't for me, anyways. After consultation, I think we've finally got a good (and hopefully effective) program in place for Dorado. If we're not happy with the results, we'll adjust accordingly.

With all the different management options out there, I'm curious about what tactics other older horse owners employ. What deworming regimen do you use on your equine seniors, and why?