Horses

Horse Poll Evil and Fistulous Withers

Poll evil and fistulous withers are painful chronic infections involving bursae in horses. Understanding causes and treatment options helps owners address these serious welfare conditions.

Key Facts

Poll evil involves infected bursa at the poll (top of head) and fistulous withers involves the supraspinous bursa
Brucella abortus infection, Onchocerca parasites and trauma are associated causes
Chronic cases show draining tracts, swelling and significant pain on head and neck movement
Surgical drainage and debridement combined with appropriate antibiotic treatment is required
Brucella-positive cases require special handling precautions due to zoonotic transmission risk

Welfare Considerations

Poll evil and fistulous withers cause chronic pain that affects the horse's ability to move the head and neck normally, interfering with eating, tack use and social behavior. The chronic draining nature of these conditions without treatment causes prolonged suffering. Early veterinary assessment and appropriate surgical and medical management prevents progression to severe chronic disease.

What You Can Do

Seek veterinary assessment for any horse with swelling, heat or draining tracts at the poll or withers
Test for Brucella before beginning treatment and follow appropriate biosafety precautions
Follow veterinary instructions for surgical aftercare including wound management and antibiotic courses
Ensure tack does not cause repeated trauma to the poll or withers area which can trigger bursitis
Maintain vaccination programs that reduce Brucella risk where the disease is endemic