Poll evil is a serious infectious bursitis at the poll that requires prompt veterinary intervention to prevent chronic welfare problems from established deep infection.
Poll evil causes significant, often severely debilitating pain that affects every aspect of the horse's function. The infection at the poll means that normal head movements cause pain, eating hay from the floor is uncomfortable, and any pressure on the poll from headcollars or bridling causes acute distress. Established cases with fistulae formation require extended courses of treatment and may result in permanent scarring and sensitivity. The welfare priority is early diagnosis and treatment before the infection extends and before fistulae form — progression to chronic poll evil represents preventable suffering.