What’s Biting Your Horse?

flies that bother horses, keeping flies off horse, flies on horse eyes, diseases flies equine, fly masks

By Kathy Smith

Flies can be a major nuisance to your horse during the summer months, and can also carry diseases and cause allergic reactions.

But your horse doesn’t have to simply put up with the winged pests causing him stress, skin reactions, or worse. You can fight back by implementing a pest control plan to help keep the buzzing battalions at bay so you and your horses can enjoy the summer more.

The key to effective fly control is knowing which type of fly is attacking your horse, and choosing the product, repellent, fly mask, or fly sheet that affords the best protection. Horses are attacked by seven basic species of flies, and each prefers a different part of a horse’s body. House flies and face flies for example, 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. 

flies that bother horses, keeping flies off horse, flies on horse eyes, diseases flies equine, fly masks

Annoying face flies can be kept at bay with the use of a fly mask. Credit: CanStockPhoto/Perutskyi

Fly ID

house fly

House Fly — Breed in manure piles, spilled feed and other moist, warm decaying organic matter. Dull grey with four black stripes on the thorax, reaching an adult length of a quarter of an inch in length. 

Stable Fly

Stable Fly — Breed in wet straw and manure, spilled feed and other types of decaying vegetation. Similar to house flies in size, yet dark grey, with seven circular dark spots on abdomen’s upper surface. From under the head, the adult’s piercing mouthparts protrude.

 deer fly

Deer Fly — Tan or dark colour, but can be green. Slightly smaller than horse flies, but larger than house flies, with brown-banded wings and piercing mouthparts. Both horse flies and deer flies lay eggs on vegetation near marshes, ponds and streams and females cut through animal’s skin with knife-like mouth parts to feed on blood as it pools. 

Horse Fly

Horse Fly — Dark colour, quite large, clear wings, big eyes and produces loud buzzing noise. Females have piercing mouthparts, while males feed on pollen. 

Bot fly

Bot Fly — Flies lay eggs on hair of horses from mid-June until frost. Larvae burrow into horses’s lips and gums and after 3-6 weeks are passed into the stomach and intestine where they remain attached until the following summer. Mature larvae pass with feces, pupate, and adult flies emerge early summer to repeat the cycle. They appear in horse manure maggot-like with spines. Adults look like skinny honey bees.

 horn fly

Horn Fly — Dark grey and half the size of house flies, with piercing mouthparts to obtain blood meals. Unlike most other flies, horn flies remain on animals almost constantly.

  face fly

Face Fly — A nonbiting fly resembling a house fly. They cluster around animal’s eyes, nose and muzzle causing extreme annoyance, and gather around wounds to feed on blood.

Related: How to Get Ticked Off - Horses and Ticks

Main Photo: CanStockPhotoInc/Maggy