Types of Horse Flies

There are a wide variety of flies that can bother or cause problems for horses. All horse flies cannot be treated the same, and most horse fly control methods are dependent on the fly’s lifecycle and habitat. Here is a brief list of common fly pests for horses and how to treat them.

Biting Flies:

• Stable Flies: Stable flies are very annoying to both people and stable animals. They bite and feed on the blood, usually on lower parts of animals, like belly and legs. They lay eggs in decomposing organic matter, like excrement mixed with straw or soil, wet straw, hay, grass clippings, etc. This means the key aspect to stable fly control is sanitation; by cleaning up the breeding materials, you will be able to break the life cycle of these flies in your stables. Clean up manure, wet feed, old hay, and anything that could harbor fly larvae once a week. Dry out manure to keep flies from laying eggs in it. Chemical control methods include using a combination of residual surface treatments and knockdown sprays. This will get rid of existing flies and keep them away for a few weeks. On-animal products give animals immediate relief but don’t last very long.
• Horse and Deer Flies: These flies can inflict painful bites on both humans and horses. Since they breed in or near water, horse and deer flies are a particularly a problem if animals are grazing or pastured in low wet areas or near streams. These flies are very difficult to control, but on-animal treatment repellents and sprays can help give animals relief.
• Black Flies: Also called buffalo gnats, these small black flies are found in pasture areas or along streams. The bites these flies inflict cause irritation, anemia, and in severe situations even toxemia and anaphylactic shock. You could try stabling horses during the day and let them pasture at night to avoid black flies, and use petroleum jelly or insecticide product on ears to prevent bites.
• Horn Flies: Although horn flies are usually cattle pests, when cows and horses are pastured together, the horn flies will move to the horses and begin to bother them. Self-treating devices have been shown to be effective, and also sprays and wipes. If it becomes a problem, avoid pasturing cattle and horses together.

Nuisance Flies:

• Houseflies: Houseflies bother everyone involved. While they don’t cause injury, they’re known to be vectors of many diseases and can lead to unsanitary conditions. Their control is extremely similar to stable flies; they have very similar breeding habits and lay eggs in the same kind of materials. Houseflies can also be trapped with baits or with sticky traps.
• Face flies: These flies are usually pests of grazing cattle, but can bother horses when cattle and horses are grazing together. They feed on facial secretions and can transmit pathogens. Wipes or sprays formulated for these flies can help reduce flies on the face, but keeping cows and horses apart will help to eliminate face flies on horses.

Learn more about using insecticides to combat flying pests around horses in our guide to using insecticides around animals.