Sweet itch (summer seasonal recurrent dermatitis or SSRD) is a chronic allergic skin condition affecting horses worldwide, causing intense itching and significant welfare harms through self-trauma and recurrent suffering.
Sweet itch is a chronic welfare condition that causes recurrent, often severe suffering for affected horses throughout spring and summer - a period covering months of each year for the horse's entire life. The welfare impact is significant: affected horses experience intense pruritus (itching) that drives frantic, persistent self-rubbing against any available surface. This produces secondary wounds, skin infections, and progressive scarring that add pain to the primary itch. Left unmanaged, sweet itch horses have severely compromised skin and coat condition with wounds around the mane and tail. The behavioral impact includes anxiety, irritability, and reluctance to be near fences or walls associated with rubbing. Management requires sustained commitment from owners, and the best welfare outcomes come from proactive prevention of midge exposure rather than reactive treatment of symptoms.