Horse Sweet Itch Welfare | Animal Welfare Hub

Sweet itch (insect bite hypersensitivity) causes intense, chronic itching in affected horses, leading to self-trauma and misery that significantly impairs quality of life throughout the midge season.

Key Facts

Sweet itch is caused by hypersensitivity to the saliva of biting midges (Culicoides species)
It affects approximately 5% of horses in the UK and similar proportions globally in affected climates
Affected horses rub their manes and tails relentlessly, causing extensive hair and skin damage
The condition is seasonal but may extend for 6-8 months in warm climates
Management is primarily preventive - keeping horses away from midges using rugs, fly repellents, and stable management
There is no cure, but desensitization immunotherapy is being investigated

Welfare Considerations

Sweet itch causes intense, constant pruritus during the midge season that dominates affected horses' lives. The drive to rub mane and tail areas is overwhelming - horses may rub raw patches down to bleeding skin in search of relief. The psychological distress of constant itching without relief is significant. Secondary skin infections in damaged areas add painful complications. Horses with sweet itch are uncomfortable throughout the warmest months of the year - typically the best grazing season - when their condition is worst. Protective management reduces but rarely eliminates the welfare burden.

What You Can Do

Use whole-body sweet itch rugs with fine mesh that exclude midges during peak midge activity (dawn and dusk)
Apply insect repellent specifically formulated for Culicoides to all exposed skin
Stable horses during peak midge activity and use fans in stables - midges are weak fliers
Avoid fields near standing water where midges breed, particularly in the evening
Discuss antihistamine or corticosteroid treatment with your vet for severely affected horses
Investigate immunotherapy options with a veterinary dermatologist for horses with severe disease