Sweet itch (equine insect bite hypersensitivity) causes intense pruritus in affected horses, leading to self-trauma, skin damage, and chronic distress. Management requires reducing Culicoides midge exposure.
Sweet itch causes severe welfare compromise through relentless pruritus that affected horses cannot ignore. The urge to rub is overwhelming, and horses will rub against any available surface - fences, trees, other horses - until skin is broken and bleeding. The resulting wounds become painful, attract flies, and can become secondarily infected, adding pain to the existing pruritus. The condition is chronic and returns each midge season, with sensitivity typically worsening over time. Sleep disruption from nocturnal pruritus adds another welfare dimension. Management is demanding and requires year-round commitment: rugs must be fitted before midge season begins and maintained throughout, stabling during peak midge activity periods, and careful wound management. Despite appropriate management, some severely affected horses suffer significantly throughout summer, raising ethical questions about breeding decisions in highly susceptible lineages.