Sweet itch (equine insect bite hypersensitivity) causes severe pruritus and self-mutilation in affected horses, representing a significant welfare challenge requiring active management.
Sweet itch is one of the most welfare-significant skin conditions in horses because of the intensity of the pruritus and the self-perpetuating nature of the condition. Affected horses experience constant itching that drives obsessive rubbing against any available surface, causing progressive skin damage, hair loss, and open wounds that become infected. The cycle of itch-rub-damage-infection creates chronic suffering that can persist for the horse's entire life once established. The welfare management imperative is proactive: preventing the sensitization cascade by protecting susceptible horses from midge exposure before the condition becomes established, and providing rigorous protection once it has developed. Horses with severe, uncontrolled sweet itch experience welfare compromise comparable to poorly managed chronic pain in companion animals.