Fecal Egg Count and Deworming

A very important item to pay attention to for our horses is if they have parasites in them that affect their health. When it comes to worms, and there are a quite a few different kinds to watch out for but the main issue is weight gain. There are some people that just look at a horse and think they can tell it’s “wormy”, and in some cases it does happen to be easy to tell, in others it isn’t. The definitive way to know though is to do a fecal egg count.

When it comes to dealing with deworming a lot of people just set their horse on a particular schedule and stay the course to make sure their horse doesn’t get worms. The fecal egg count test is an excellent way to tell whether or not you need to waste your time and money with sometimes very pricey medicine that your horse may never need. The other thing about deworming is that you are essentially putting poison in your horse to kill off the eggs and worms that are living in there, but there is no mistake when we say, it isn’t good for the horse either.

The fecal egg count test can be done by any veterinarian and it’s usually inexpensive, but you have to get them the manure to do it with. That’s ok if they are local, but if they are a ways out then you have to either pay them to come get it or deliver it. Fecal egg count tests don’t take long at all and usually you can know within an hour of the test starting. Which then leads into scheduling of the vet or assistant to know what is happening. There are other para-professionals, like ourselves here at Stable, that do the job but it’s not that hard to do yourself if you have the equipment and know what to look for.

The primary requirements for doing such a test would be a fecal egg count test kit that comes with come marked containers for the flotation solution. Then a couple of small syringes and slides to put the samples on. We like using the McMaster set that Chalex sells online because it comes with handy grid lines to do the counting with. That said though, it doesn’t take much time with a trained eye to spot a high egg shedder. If a horse is shedding a high amount of eggs then it’s an educated guess that there are a lot of worms in there too.

You’ll need a decent microscope with a 100X magnification ability and then patience and time to build experience and confidence when trying to find the eggs. While describing exactly how to go about doing the test falls outside of this particular article, with practice doing such a test can be quite empowering and if done enough times, economical. If you have more than a couple of horses then the value adds up, outside of that it may not be worth it as you may have a low shedder and not need to test often at all.

When we refer to a horse being a low or high shedder, we’re talking about the amount of eggs that are detected in the manure being sampled from. The idea is that the eggs are floated in the flotation solution after being mixed up with a particular amount of manure. They get counted and a calculation is done based on the amount of flotation solution and manure being sampled and a number comes out of eggs per gram. In cases that there is less than 200, the horse is generally fine. More than that and up to about 500, the horse should be treated mildly, more than 500 and it’s getting serious.

Here’s a picture of one of the types of eggs to be found:

[responsive]Simple strongyle in horse manure[/responsive]

Here is a close up of the one in the featured image of this article:

[responsive]Strongyle close up with 100X magnification[/responsive]

While there are many types of eggs to be found, this is the most common. Once the count is done and it has been determined that the horse is a mid to high shedder then action needs to be taken. For high shedders we generally recommend using Ivermectin once and going from there. Again, it’s important to note that the egg count is not a strong determination of how many worms a horse may have and how it’s actually being affected. The general consensus is though that other horses and the pasture can be affected badly by high shedders and even though that horse may be able to handle the parasites just fine, it doesn’t mean others will. It’s the responsible thing to do either way to reduce the amount of eggs in your horse.

When we do our tests we make sure to do two completely different tests from two different samples. Each test consists of two slides with two grids per slide. When we come out of a test we’re very sure of how many are in the horse and can make a strong recommendation on what to do, but it’s important to say that we at the same time strongly recommend communicating with your veterinarian to double check. A second test by the vet may be needed if there is any doubt and it doesn’t hurt to have it done, except in cost of course. The health of the horse and the herd may be at stake though, so it’s a small investment in long term gain.

For treatment, as mentioned above, a one time administration of Ivermectin and then retesting in a couple of weeks happens. The results of that test will determine if management needs to happen or further medicine (poison) treatment needs to happen. It’s possible that the eggs may be immune to the chemical used and not be effective against the worms, in such a case another may be tried. If all goes as expected though and the egg count is reduced significantly then we would call that a success and move to management through diet.

To wrap things up, at minimum the health of just one horse is on the line when it comes to figuring out if it has worms or not. A more drastic case though is that one horse can affect a whole pasture of horses and infect them all. Some may handle the parasites quite well, while others will not. The ones that don’t will then need more health care and possible rehabilitation, which in the end can be much more costly to a quick 10 to 20 dollar cost of a fecal egg count test. This is why every horse in our care is tested for free as it seems that doing the egg count test just isn’t as common as we’d like it to be and we’re looking for your horse to be as healthy as it can be when we’re done working with it. Either way, if this is something you haven’t considered or have mildly considered, we say don’t delay. It’s simple and easy to get done and once you know, then you know. It will only help your horse to be more informed.