Allergen-specific immunotherapy for equine sweet itch (culicoides hypersensitivity) offers the possibility of long-term desensitization for severely affected horses.
Sweet itch causes extreme, chronic welfare harm through the intensity of itching that drives affected horses to rub themselves until they bleed. The condition typically worsens each season as sensitization increases with repeated exposure. Current management — rugs, stabling, repellents — reduces but cannot eliminate exposure in most practical situations. Immunotherapy that reduces the underlying hypersensitivity offers the prospect of horses who can tolerate midge exposure without extreme pruritic responses — a qualitative welfare improvement rather than management of symptoms. The welfare aspiration for severely affected horses is desensitization, not indefinite symptom management.