In warm months, it seems like flies and other biting insects are always the #1 enemy of horses. They annoy, they bite, they cause itching, bumps, swelling and skin reactions. Often times horse owners go to great lengths to lessen the impact of flies on their horses. But can what you feed your horse actually have an impact on your fly population?

There are fly preventatives that may work for some horse owners which involve feeding a certain ingredient to the horse. Many people claim that giving apple cider vinegar daily will keep the flies away, while others swear by garlic powder or brewer’s yeast. The fact more often than not is that it is very difficult to get the horse to eat enough of these items to make a difference where flies are concerned because they typically have a strong taste and smell; the trick is getting the horse to ingest them at all. The important thing to remember is that horses are all unique and what works for your neighbor’s horse may not have the same effect on your horse.

Another alternative to feed the flies away is using a feed through IGR additive that is labeled for horses. This active ingredient does not get absorbed by the gut, but instead passes through into the manure, hence the “feed through” name. Once in the manure, the Insect Growth Regulator (IGR) causes the fly pupae to not mature into adult flies. With disciplined feeding, these products can be effective but may be expensive. One warning with this type of fly control – if you have close neighbors who aren’t controlling their fly populations you will likely see little difference because their flies will continue to come snack on your horse.

More traditional methods of fly control should not be discounted, including finding an effective fly spray, using fly sheets, and changing turn out times to when flies are less active. Cleanliness in your stable and proper manure management can also have an impact on fly populations.