Horse Sweet Itch: Welfare and Management

Managing sweet itch (insect hypersensitivity) in horses to reduce suffering from this intensely pruritic allergic skin condition.

Key Facts

Sweet itch is caused by hypersensitivity to the saliva of Culicoides midges and affects approximately 5-10% of horses in Northern Europe
Affected horses rub intensely against any available surface, causing hair loss, skin thickening, and open wounds in severe cases
Culicoides midges are most active at dawn and dusk, and are found primarily in still, humid conditions near water
Specialist full-body sweet itch rugs (Boett rugs) covering the mane, face, and tail significantly reduce midge access when worn throughout the high-risk period
Stable management including housing at midge-active times, using fine-mesh stable screens, and fan ventilation substantially reduces exposure
There is currently no cure — management focuses on minimizing midge exposure and reducing the inflammatory response once it occurs

Welfare Considerations

Sweet itch causes extreme suffering in affected horses through unrelenting pruritus that can dominate every waking moment during midge season. The compulsive rubbing behavior leads to self-inflicted injuries as severe as any external wound, and the condition often worsens with age. Unlike many chronic diseases, sweet itch is not immediately life-threatening, which can lead owners to underestimate its welfare impact. In reality, severely affected horses have profoundly compromised quality of life for 4-6 months of the year. Management requires commitment to a multi-faceted approach combining physical barriers to midge access, appropriate timing of stabling or turnout, and veterinary management of secondary skin infections. Immunotherapy trials are showing promise but are not yet widely available.

What You Can Do

Invest in a well-fitted sweet itch rug for affected horses and ensure it is worn consistently during the high-risk midge season
Stable your horse during peak midge activity (dawn and dusk) during summer months, using fine-mesh screens on stable openings
Consult your veterinarian about appropriate treatments for secondary skin infections and any medicinal options for itch relief
Move horses away from water features and low-lying fields where Culicoides midges breed, if paddock options allow
Consider whether a move to a drier, less midge-prone environment is feasible for severely affected horses