A Scratch for Every Itch - Horses scratch for many reasons. They scratch themselves on fences, rub up against posts (and sometimes people), roll on the ground, and groom each other. A natural behaviour usually linked to social bonding, comfort, and relaxation, it can be heightened seasonally by shedding, sweating, or the presence of insects. However, when scratching becomes frequent enough to result in hair loss, broken skin, scabs, or if it disrupts eating or sleeping, it is time to talk to a veterinarian to determine if a skin allergy is to blame so appropriate treatments can be pursued.