Flies, Worms and Yucky Things

 A fan in the stall or in the barn aisle can also be a huge help in preventing pests from bothering your horse (make sure to use a fan rated for farm or industrial use so the motor is sealed off from dust and there is less risk of fire).

Parasites

Internal parasites, also called worms, are common in horses because immature worms (larvae) live on blades of grass and are passively eaten when a horse grazes. Larvae emerge in pastures in the spring. These larvae then develop into adult worms within the horse’s intestines.

While this sounds gross, it’s really important to realize that a small number of worms typically does not harm a healthy adult horse. However, large worm infections can cause problems, like diarrhea, weight loss and sometimes colic.

Equine parasite control can be done with one of several deworming drugs made for this purpose, but not all horses need to be treated. So how do you know if your horse needs a dewormer?

Your vet can help you select a dewormer after doing a fecal egg count. Photo by Gina Cioli

In the spring, ask your vet to do a test called a fecal egg count. To do this, your vet will take a sample of your horse’s manure, mix it with a special liquid, and look at the sample under a microscope. Parasite eggs are shed in your horse’s manure, so if your horse has worms, their eggs are seen as small oval shapes under the microscope.

Don’t worry if your horse’s manure is positive for eggs; this is very common. What’s most important is the number of eggs. Your vet will count them and tell you how many she finds. If there are many eggs—typically over 200—your vet may recommend treating your horse with a dewormer.

If there are fewer eggs, this indicates a mild infection, and your horse typically won’t need treatment unless he is young or otherwise sick. Not overusing dewormers helps prevent the development of resistance by the parasite to these important drugs.

To help control worms on the farm, remove manure piles in small pastures and paddocks to prevent the spread of worm eggs. Not allowing your horse to overgraze a pasture is important, too. Grass should be kept about 3 to 4 inches tall—shorter than that and it’s time to move your horse to another field, if possible, to allow the grass to re-grow.

With a little planning and awareness, you and your horse can be worry-free from worms and flies this spring!