By Melanie Huggett

A large number of flying insects emerge with the heat each summer, and they can turn what should be long luxurious days in the ring, field or trails into painful, frustrating or itchy endeavours! While irritation may seem like a minimal concern, excessive flies can cause stress in horses, which can lead to reduced performance and malnutrition. Not only can insects be bothersome, but bug bites can cause a variety of allergic type skin reactions in many horses. The condition known as Sweet Itch or Summer Eczema is caused by midge flies, for example. Some flies and mosquitoes may even carry diseases such as West Nile virus, equine infectious anemia, and equine encephalomyelitis.

House flies and face flies are two of the most common flies found around horses. They feed on moist secretions from the eyes, nose, vulva and prepuce, and can be extremely irritating to horses. Photo: ©CanStockPhoto/Pakhnyushchyy

It is important to have a pest management plan in place to help protect your horse against undue stress and other health conditions. Fortunately, most fly control methods are easy and not time consuming, and so there should be no hesitation to incorporate them into your routines.

Prevention and Protection

Routine deworming and vaccinations are extremely important to protect against internal parasites and deadly diseases that may be transported by flies.

Contact your veterinarian and make sure your horse is kept up to date.

Hygiene

Improving hygiene around the barn is the best way to reduce fly numbers. As many fly species lay their eggs in manure, moist areas, and rotting vegetation, it’s important to remove manure and soiled bedding frequently. Clean up any spilled or uneaten feed from the floor and corners of buckets or troughs, as this may also attract flies. Water containers should also be cleaned regularly, and scrubbed free of dirt and algae. Place waste piles as far away from the barn as possible. Manure piles that are hot (above 140 degrees) are ideal, as developing flies are unable to survive at such high temperatures. You can create a hot compost pile by building a three-sided structure and packing manure tightly. Conversely, spread manure out thinly in an unoccupied field, so it dries out and can decompose quickly into the ground.

Flies are more than a nuisance; they can carry diseases and cause uncomfortable allergy-like reactions.

To protect against mosquitoes, make sure to remove any standing water around your property that may act as breeding sites. Tip over buckets, old tires, or other containers. Even small pockets of standing water, such as an upside down lid, can act as mosquito nurseries. Check around paddocks, driveways and under vegetation for puddles, and fill them up with topsoil.

Chemical Methods

A number of chemicals and natural formulas exist to both kill off flies and keep them away. It is important to avoid getting them in the eyes or mucous membranes when applying them to your horse. Insecticides are effective, and can be sprayed on surfaces around the barn, on manure piles, or on the horse itself. Insecticides can contain both synthetic chemicals, as well as natural chemicals such as pyrethrin, a plant extract. However, while effective in killing a wide variety of pests, many insecticides have begun to lose favour by individuals who worry about their possible toxic effects, impact on beneficial insect species, and bioaccumulation.

Another chemical means of protecting against insects is repellents. There are a wide variety of natural repellent formulas available, which contain things like citronella and plant extracts. Both garlic and apple cider vinegar can repel flies effectively. Apple cider vinegar can be added to a horse’s drinking water, or included with a horse’s grain for an “inside out” repellent. There are also topical sprays that contain these ingredients.

Physical barriers, such as a fly mask, are a great way to protect your horse against all types of flies.

Physical Barriers

Deer and horse flies are more difficult to deal with than most fly species. These flies can travel long distances, and insecticides and repellents are also ineffective because they land to feed for only a short time. Physical protection of the horse by using fly masks and sheets is the best protection against these flies, as well as protecting against all other fly species. Horses with sensitive skin or horses that are prone to allergic type reactions should wear masks and sheets whenever let outside during the daytime. There is also fly protection available for the neck, belly and legs if further protection is needed.

Predators and Parasitic Insects

Encouraging or importing insect predators has become an increasingly common way to deal with pests. Not only is it effective, but creating habitat for local bug-eating species is good for the environment as well. A number of bat species feed exclusively on insects, devouring more bugs than birds or electric zappers. A single brown bat can consume between 3000 and 7000 mosquitoes in a night, with larger populations consuming thousands of tons of potentially harmful pests annually.

Bat houses entice insect-eating bats into nesting on your property. They can be hung from trees, or attached to the side of buildings.

Bats are misunderstood by many, being considered a menace when in fact they are extremely helpful. To encourage bats to take up residence around your farm, you may want to install bat houses.

Goldfish work wonders in drinking troughs and ponds! The fish will eat any insect or larvae in the water, keeping it clean and free from flies. The fish have no negative affects on horses, but should only be kept in larger water containers where they have plenty of room.

Releasing parasitic insects, usually tiny, stingless wasps, is also very effective at reducing a large number of fly species. However, because their lifecycle is short, a new batch needs to be released every two weeks.

Other Methods

Sticky traps are also commonly used and highly effective against flies. Make sure to replace them every few weeks as they will quickly clog up with dust and dead flies. Fans can also be used indoors. Most flies don’t like moving air, and a blowing fan will discourage them from entering the area. Proper safety precautions should be taken, however: make sure the fan is placed away from any place a horse may accidentally step on the cord or knock it over. Altering normal patterns can also be effective in protecting your horse against flies. The majority of fly species are active during the day when there is bright sun, so letting your horse out into its pasture or paddock at night and stalling during the day is one way to reduce the chances of irritating flies. Midge flies are most active at dawn and dusk, so horses prone to Sweet Itch should be stalled or more heavily protected during those times. Lastly, mosquitoes are most active during the night. Adjust your turnout schedules according to what sensitivities your horses might have.

Whatever your method, pest control management is an important and necessary part of summer horse care to protect your companions from stress, skin reactions, and diseases. Remember your summer by long rides in the summer sun, not by the number of ways in which flies interfered or annoyed you!

Homemade Fly Repellent

Fortunately, it is very simple to make your own fly repellent using easy to find ingredients. There are a number of recipes, but most include a variation of similar ingredients. Below is an example of what a homemade fly repellant might include. Make sure to reapply often for best results, and avoid contact with eyes or mucous membranes.

• 1 cup water
• 1 cup Avon Skin So Soft bath oil
• 2 cups vinegar
• 1 tbsp Eucalyptus oil
• 3 tbsp pure Citronella oil (optional)

Mix all ingredients together and put in clean spray bottle. Be sure to check to see if your horse (or yourself) is sensitive to any of the ingredients before using.

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