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Green fly control

These fly masks are available at Horse N Hound as well as many others in varying sizes and colors.

This article was originally published in the Las Cruces Bulletin on April 17, 2015

By Katharine Lark Chrisley

The warm weather brings positive energies for horse persons, but one negative – the flies. While we want to eliminate these buzzing nuisances, some of the chemical remedies can create worse problems than the flies themselves. We want to address the fly issue by repelling them from our horses and by killing them on our premises. There are many effective solutions, other than deadly poisons, which have been known to cause health issues in the animals and for the environment. There are fly trap bags that can be hung in shady places, baited with stinky liquid and left to capture thousands of insects through their “come in but can’t go out” attachments. The only danger these present is to our sense of smell. Here, in the high desert, the sticky, fly paper- type traps tend to dry up and become useless in a day or two. I add one tablespoon of diatomaceous earth (DE) daily to each horse’s bucket of feed. It acts to prevent the fly population developing in the manure. The DE is a source of minerals and is safe to feed if designated “food grade.” It also works to eliminate internal worms when fed in slightly higher doses. It has a mechanical action that slices up the developing larvae, which means you want to avoid inhaling DE or getting it into your or your horse’s eyes. I always moisten the food after adding it. There are also actual fly predators – tiny, harmless insects that kill flies you can purchase monthly to release around your property. A fly spray to use directly on the horses can be made by mixing 40 drops essential oil of cedar wood, 20 drops eucalyptus oil, 20 drops rosemary oil, 20 drops patchouli oil and 20 drops peppermint oil to a onequart sprayer. Fill the sprayer half way with apple cider vinegar and the rest pure water. If mosquitoes are a problem, add 40 drops geranium oil and 40 drops citronella oil – make sure all are essential oils. Shake well before each use and patch test it on the horse’s neck at first, one hour before full-body use. When the flies become intolerable, a commercial spray with natural pyrethrins (from chrysanthemums) is a safer choice than sprays with synthetic (pyrethrum) or complex chemicals. The equine fly masks, which look like blindfolds but are as easy to see through as window screens, become essential to protect eyes. Flies will cause eye irritation and even infection. The masks are also protection from wind, dirt and debris thrown up by weed trimmers, mowers and such.

Flies can cause serious sores on a horse’s belly. Press powdered rosemary herb up onto the sores. This heals with disinfecting phenol and repels the bugs. Other parasites, such as ticks, can get into equine ears and cause misery. If a horse’s personality suddenly changes, check his ears. I use Camphophenic gel from the pharmacy, applied by hand into each ear to repel parasites and soothe the tissues. Some people pour Lindane – a serious poison – into the ears. This will kill ticks, but is absorbed into the horse’s body as well. There are safe and effective remedies to use that will bring peace to your horses without the toxic side effects and long-term damage associated with pesticides. There is more information on green horse-keeping at

Katharine Chrisley is a lifelong horsewoman, equine specialist, instructor and trainer. For more information, visit

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