As many of you know I am a proponent of doing routine fecal egg counts as opposed to actually deworming your horse every month with an antiparasite medication. Which means sending in horse manure samples to a lab or your vet (who sends them to a lab) and determining how many parasite eggs are seen in the sample. If there are only a couple or none it can be reasonably accepted that your horse has a low count of parasites (a lot of factors do play into this, I am oversimplifying here). If there are more than a couple of eggs in the fecal sample then it gives you a reason to deworm your horse with an antiparasite medication, such as Ivermectin, Fenbendazole, etc.

Now granted if your horse lives in a small pasture that has multiple horses, more than 1 horse per acre, you may have no choice but to give your horse deworming medication on a monthly basis. A lot depends on the immune system and digestive system of the horse and the actual parasite load of the pasture itself as to if you will have to deworm monthly. Still I really promote using companies such as Horsemen’s Laboratory on a regular basis even if you are deworming regularly, as it will help determine if your deworming program is actually even working.

For the majority of performance horses that are stall kept and are either out on large pastures, turned out in dry lots, or have a single pasture to themselves, these horses would have no benefit of using deworming products on a regular basis, because they just do not have exposure to parasites, and in fact, you would, in most cases, be over treating which has been implicated in affecting the immune system against other parasites such as EPM (not proven just implicated) or in the face of a real parasite infestation your horse could become debilitated rather quickly. Fecal egg counts on a monthly or every other month basis would be sufficient to know whether or not you even need to treat your horse. The one thing that really needs to be focused on here is parasite control for the improvement of your horse’s health; not total annihilation of every parasite in your horse’s digestive system. Horses have maintained a balance with parasites for thousands of years; it is just recently that due to mans domestication and concentration of horses in one location that intestinal parasites have become a factor in horse health and well being. Fecal egg counts are a good means of determining how much control we have in parasite loads of our horses.

The Horse has a great article on fecal egg counts –>Fecal Egg Count Exams Offer Useful Information for Horse Health Management.
It explains in detail the limitations of using fecal egg counts but also relates the important message that fecal egg counts are the gold standard when testing for parasite infestation of your horse and most importantly -

Parasitologists generally agree that the proper objective of parasite control is to maintain the parasite burden at a low level, rather than to eliminate parasites entirely. This middle ground avoids over-treatment, limits the cost of parasite control, and helps horses maintain partial immunity to overwhelming infection. In other words, it’s a good idea to allow a very low level of parasite infection so that horses’ immune systems can learn to deal with these invaders if they occur in larger numbers.

Just for this quote alone the article is worth a read and a reread. And what I am completely impressed with is the veterinarian quoted in the article is from a pharmaceutical company, maybe they are not all out just for the company…LOL. So for improving your horses health look to do more fecal egg counts rather than just medicating your horse and even if you are medicating your horse do fecal egg counts to determine the effectiveness of your program.