If you’re like most riders, you’re probably not terribly enthusiastic about picking through your horse’s latest gift of road apples. But like it or not, any natural horsekeeping or deworming program should include regular fecal tests. This simple test can save you money and improve your horse’s health by ensuring you don’t bombard his system with unnecessary chemicals.

Fecal tests are typically not routinely recommended by local veterinarians, so it’s no surprise that many riders do not understand what this test is and what it does. To help us understand why this test is so important, we talked with veterinarian Dan Moore.

How often should riders have a fecal test done on a healthy horse?

DM: This depends on the age and condition of the horse, as well as prior fecal results. Older horses generally have fewer issues, due to a natural worm resistance that has developed over time. Young horses, especially those under three years of age, need more frequent testing. Quite often, we will deworm a young horse that appears wormy (poor hair coat, pot belly) even if no parasites are seen on the fecal exam.

As a rule of thumb, we suggest fecals be done a minimum of four times a year for adult horses. If a horse is under three, every other month is best. This schedule should be followed until there are no parasites, or until very low numbers are seen on a few consecutive samples. Then, and only then, can the time between samples be increased. It is not uncommon, even in a herd situation, to find many horses that are always negative, or almost always negative, in their worm counts. Such horses have either developed a resistant immunity, or are simply no longer being exposed to the worms. If no or very low numbers are consistently seen on fecals, you can increase the length of time between testing. Conversely, if you consistently find positive results in a horse, then test more often and consider boosting the immune system.

Veterinarians and riders in general have got into the habit of deworming because the calendar says it’s time to do so, without considering the negative consequences. Resistant “super worms” are being created by such practices, and the immune system and general health of the horse may be threatened. All one has to do is listen to a pharmaceutical commercial on TV to realize that all drugs have some consequence. This common sense seems to have been forgotten when it comes to traditional deworming recommendations.

How should one go about collecting a fecal sample from a horse?

DM: Collecting a sample is as simple as picking up a small amount of fecal material and putting it in a sealed bag. Ziploc type bags work well, and even work as a glove if turned inside out while picking up the sample. Properly label the bag with your horse’s name, your name, address, and date of collection. The sooner you get the sample to your veterinarian, the better. However, we frequently have samples mailed from as far away as Hawaii. These may take a week or more to arrive by first class mail. As long as the sample has been sealed properly and has not dried out, we can get great results.

Are there any factors that can affect the test’s accuracy?

DM: The factor with the most negative impact would be a dried out sample. If such are received at our lab, we ask for new samples to be sent. Improper labeling can also be an issue. Occasionally we will receive a “group sample”, where samples from multiple horses in the same herd were mixed together to be tested. These we refuse to test – just because there are worms present in some horses, doesn’t mean all the horses in the herd are positive. Such thinking completely disregards individual immunity and resistance. For the most part, all horses are exposed to parasites on a regular basis, but that does not mean they should be dewormed “just because”, any more than we should be treated with antibiotics every time we are exposed to the flu.

Will my veterinarian collect a sample during a routine visit or annual exam?

DM: Many veterinarians will not even do fecals on horses. Unfortunately, they have bought into the misunderstanding that all horses have worms all the time. They will frequently tell their clients that fecal tests are ineffective and it is best to simply deworm on a calendar basis. This practice has led to a resistance issue, and what I refer to as “super worms”. Fortunately, this is changing, and the need and recommendation to do fecals is trickling down from parasitologists to vet schools, and finally reaching veterinarians in the field.

What process does a fecal test typically follow?

DM: At our practice, we do a fecal flotation test that concentrates any eggs. We have a veterinary microbiologist review the samples – it is important to have someone who frequently does fecal exams to do the testing. Equine samples are much more difficult to read than dog or cat fecals.

What worms, if any, may not be visible in a sample?

DM: Tapeworms, bots, and parasites that are migrating through tissue (encysted larvae) may not show up.

How do you interpret test results?

DM: A positive test indicates that worms are present. Generally, if we find more than two or three eggs per slide, we suggest deworming. Of course, we suggest a more natural approach over chemical dewormers.

If a worm overload is discovered, and the horse is dewormed, should he have another fecal test done afterwards?

DM: Yes. I would suggest a follow-up in three to four weeks.

Any deworming program, whether chemical, natural or combined, should include regular fecal tests for each individual horse. These tests are easily done and relatively inexpensive. Best of all, they can save you money in unnecessary deworming products, and enhance your horse’s health and longevity.

Dr. Dan Moore graduated from Auburn School of Veterinary Medicine in 1980, then completed the Professional Course in Veterinary Homeopathy and the Advanced Course in Veterinary Homeopathy. He is the founder and developer of thenaturalhorsevet.net, an online source of information, products and services about natural and complementary alternatives for horses. Information can be obtained by calling 1-877-873-8838.

Published in the March/April 2009 issue of Equine Wellness Magazine