Sweet Itch in Horses: Management and Welfare

Sweet itch, or insect bite hypersensitivity, causes intense pruritus in horses and ponies during summer months, creating significant welfare challenges for affected animals.

Key Facts

Sweet itch is caused by hypersensitivity to the saliva of Culicoides midges
Approximately 3-5% of UK horses and ponies are affected, with higher rates in some breeds
Native breeds including Icelandics, Welsh and Fell ponies show higher prevalence
Affected horses rub mane, tail and body causing hair loss, skin thickening and wounds
Culicoides midges are most active at dawn and dusk and in humid, still conditions
Horses born and raised in endemic areas appear at lower risk of sensitisation
There is no cure - management focuses on reducing midge exposure and controlling itch
Immunotherapy protocols are under investigation but not yet widely available

Welfare Considerations

Sweet itch causes intense, chronic pruritus that can dominate an affected horse's summer months. Self-trauma from rubbing leads to open wounds, secondary infection, and severe discomfort. The condition is lifelong and can worsen with age. Welfare management requires consistent application of physical barriers (fly rugs), avoidance of peak midge times, and appropriate topical and systemic treatments. Rehoming affected animals without disclosure raises serious welfare concerns.

What You Can Do

Use appropriately fitted sweet itch rugs covering neck, belly and hindquarters in summer
Stable affected horses at dawn and dusk when midge activity peaks
Apply licensed insect repellents regularly, paying attention to mane and tail bases
Work with your vet to develop a treatment plan including antihistamines or corticosteroids if needed
Disclose sweet itch history honestly when selling or rehoming affected horses