Horse Sweet Itch: Welfare Management of Insect Hypersensitivity

Sweet itch is the most common allergic skin condition in horses, causing intense itching and self-trauma that significantly impairs welfare during warm seasons.

Key Facts

Sweet itch is caused by hypersensitivity to Culicoides midge saliva, affecting up to 5% of horses in endemic areas
Affected horses rub mane, tail, and body areas to the point of hair loss, skin thickening, and open wounds
The condition is seasonal but progressively worsens with each year of sensitization in affected horses
Certain breeds including Icelandic horses and Welsh ponies have elevated genetic susceptibility
Moving horses to high-altitude or coastal locations with fewer midges can dramatically reduce symptoms

Welfare Considerations

Sweet itch causes chronic, intense pruritus (itching) that significantly reduces quality of life during affected seasons. Management requires a combination of physical protection (fly rugs, shelter during dawn and dusk), barrier repellents, and medical management including corticosteroids or newer immunotherapy approaches. The condition is not curable but is manageable with consistent effort. Breeding decisions should account for familial susceptibility.

What You Can Do

Use appropriately fitted sweet itch rugs covering the belly and neck during midge season
Apply effective insect repellents at dusk and dawn when Culicoides midges are most active
Provide stabling during peak midge activity hours and use fans to deter midges in stables
Consult a veterinarian about appropriate anti-inflammatory or immunotherapy management