Hay Everyone!

Although it’s hard to believe, spring will be here before we know it. The warming weather brings plenty of changes including nice fresh grass which is my favorite! As we move into a new season and a new year, it’s a good time to revisit your internal parasite control plan.

The thought of creepy little worms in my digestive tract is rather disconcerting, but I’m assured it’s a normal part of life. The American Association of Equine Practitioners suggests your parasite control plan should have three major goals:

  1. Minimize the risk of disease associated with parasites;
  2. Control the amount of parasite eggs shed by your horses, and;
  3. Avoid the development of further anthelmintic resistance, if possible. (An anthelmintic is a drug used to kill parasites according to one of my friends. It’s a pretty big word, if you ask me.)

There are a number of management practices that can be implemented to reduce the chance your horse will become infected with parasites. In a perfect world, manure would be removed as soon as it appeared. (I’m told at one time this actually happened in some stables. I’m glad that wasn’t my job!) In today’s world, this may look like removing manure from pastures on a routine basis. Composting of manure and soiled bedding will kill parasites, if done properly. The heat produced during composting is what kills the parasites. Non-composted manure should not be spread on pastures as it basically spreads parasites across the pasture where your horse can then consume them and continue the life-cycle of the parasite. (Yuck!)

You also want to avoid feeding your horse near manure as the parasites can move from the manure to the feed. Some horses (and I’m NOT one of them) may defecate on or near their hay and then continue to consume the hay. Feeding hay in a container (that is horse-safe) or other similar management practices can help reduce the risk of parasite transmission.

In addition to environmental measures, administering an anthelmintic (also known as deworming your horse) can be used to help control internal parasites. To determine an appropriate deworming schedule, you should work with your horse’s veterinarian to perform a fecal egg count (FEC). A FEC is use to monitor the egg shedding status of your horse, with horses classified as low (0-200 eggs per gram), moderate (200-500 eggs per gram), or high (>500 eggs per gram) shedders. To perform a FEC, you will need to collect a fresh sample of your horse’s manure. You’ll need to store the sample in a refrigerated location in an airtight and leak-proof container (a Ziploc bag works well) until the FEC can be performed.

After implementing a deworming schedule, a fecal egg count reduction test (FERCT) should be performed to determine if your treatment was effective. The FERCT consists of a FEC from before deworming and one 14 days after deworming which are used to calculate the percent reduction in FEC following deworming. Your veterinarian can help you interpret the results, but overall a larger percentage reduction is better as it indicates less parasite resistance to the dewormer used.

As the spring sun brings our pastures back to life, take a few moments to review your parasite control plan. Which of these practices will you implement this year? Can you think of other ways to improve your plan?

Until next time.

Your Pal,







Lord Nelson

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