Equine Sweet Itch 2025: Welfare Management Update

A 2025 welfare management update for sweet itch (insect bite hypersensitivity) in horses, including the latest treatment options and management strategies.

Key Facts

Sweet itch (IBH, Insect Bite Hypersensitivity) causes intense pruritus from Culicoides midge bites — affected horses rub vigorously on fences, trees, and stable fittings, causing hair loss, wounds, and secondary infection.
Approximately 5-10% of UK horses are affected — Icelandic horses, Welsh breeds, and Shires are over-represented; the condition is lifelong and cannot be cured.
Sweet itch welfare is severe — chronic pruritus compromises behavior, sleep, body condition, and social interaction; cortisol levels are elevated throughout the midge season.
Management requires multi-modal approach: properly fitted sweet itch rugs (Boett blankets have the strongest evidence base), stabling at dawn and dusk, fly repellent application, and removal from midge-rich environments.
2025 update: A licensed equine IBH vaccine (ALLERDERM/EQUIP IBH) based on Culicoides allergen desensitization has been approved in some European markets — it reduces symptom severity by 50-70% in treated horses.
Corticosteroids (prednisolone, dexamethasone) provide significant short-term relief — they are used in severe acute cases but cannot be used long-term due to laminitis risk.
Oclacitinib (Apoquel) — licensed in dogs for pruritus — is used off-label in horses with promising results in recent case series, offering a non-steroidal anti-pruritic option.

Welfare Considerations

Sweet itch causes months of genuine suffering for affected horses every year — it is not 'just itching' but a severe dermatological condition that compromises quality of life throughout the midge season. Comprehensive management including Boett rug, stabling at dawn/dusk, and midge avoidance can dramatically reduce suffering. The emerging IBH vaccine represents a major welfare advance for affected horses.

What You Can Do

Fit affected horses with a properly sized Boett blanket from April through October for midge protection
Stable affected horses from two hours before sunset to two hours after sunrise — peak Culicoides activity periods
Discuss the emerging IBH vaccine with your vet if it becomes licensed in the UK — it offers significant welfare improvement
Apply DEET-based fly repellents to uncovered areas, particularly the mane, tail base, and belly