Sweet itch caused by Culicoides midge hypersensitivity is a chronic welfare problem for horses, and allergen-specific immunotherapy offers a promising but not universally effective treatment.
Sweet itch causes significant and prolonged welfare suffering through intense pruritus that horses cannot resist scratching against fences, trees, and any available surface. The resulting self-inflicted wounds, hair loss, and skin thickening are visible manifestations of chronic distress. The seasonal cyclical nature means affected horses suffer predictably across many years without intervention. Allergen-specific immunotherapy addresses the underlying hypersensitivity mechanism rather than merely suppressing symptoms, and in responsive horses offers meaningful long-term welfare improvement. Combination management during the midge season remains important even in horses receiving immunotherapy.