How effective are fly protectants for horses?
Flies can transmit diseases, cause welts and prompt discomfort in horses.
Horses swish their tails, stomp their feet and move their heads to remove bothersome flies.
Leggings, leg bands and citronella spray can help reduce fly aversion behaviors.
Manure management, fly masks and sheets and clean facilities can further help manage flies on your farm.
How do flies affect horses?
Stable flies are the most common flies in the upper Midwest. These flies attack horses from May through October.
Flies can harm horses by
- Transmitting viruses and diseases.
- Causing welts or skin irritation at bite sites.
- Causing hoof damage from excessive stomping.
- Prompting overall discomfort as horses try to avoid them.
Horses usually swish their tails or stomp their feet to get flies to leave. They may also try to move their heads toward their bodies or limbs or twitch their skin to get rid of them.
How to best manage flies
- Keep your facilities clean and dry.
- Remove manure and soiled bedding from horse areas often.
- Use fly protectant products on your horses such as citronella spray, leg bands or leggings.
- Provide a physical barrier between your horse and flies.
- Use nets and screens on your barn doors and windows.
- Use fly sheets and masks on your horses.
- Use residual premise sprays where flies like to perch (barn walls and ceilings).
Testing fly protectants for horses
The goal of this study was to determine which products best help horses avoid flies. We evaluated six adult horses for six weeks. Each week, an individual horse received one of the following treatments:
- Permethrin spray
- Pyrethrin spray
- Homemade citronella spray (12 oz. distilled white vinegar, 4 oz. Avon Skin So-Soft, 1 oz. citronella oil and 12 oz. water)
- Leg bands (Fly Free Zone, Inc., Newbury Park, Ca)
- Leggings (ShooFly, Stone Manufacturing and Supply Co. Inc., Kansan City, MO)
- No fly protectant
Across the six weeks, each horse received each treatment. We applied all fly protectants according to the manufacturer’s recommendations.
We observed common fly avoidance behaviors for two hours after application to evaluate how well the products worked. These behaviors included:
- Tail swishing
- Foot stomping
- Head-backs (moving the head towards the body or limbs)
- Skin twitching
We found that fly protectants reduced fly annoyance behaviors in horses. Compared to no fly protectant:
- Citronella spray reduced tail swishes and shoulder twitches.
- Leggings and leg bands reduced head-backs and hoof stomps.
We found that leggings, leg bands and the citronella spray were most effective at reducing fly avoidance behaviors. However, no one treatment reduced all of these behaviors in horses.
Effects of different fly control products on horses
|Treatment||Tail swishes/min.||Shoulder twitches/min.||Head-backs/min.||Hoof stomps/min.|
Reviewed in 2018