A tendon stretched too far and torn, resulting in a thickening where scar tissue forms. May be high or low on the tendon, causing severe lameness. The horse may recover, but the tendon will never regain full strength. Calf knees, long sloping pasterns, long toes and heels, and weak "tied-in" tendons put more strain on the tendons and may contribute to bowed tendons. However, any horse can bow a tendon through an accident or fall.