Flies and other insects cause significant distress and welfare problems for horses, and effective management significantly improves summer welfare.
Insect harassment in summer represents a significant and sometimes underrecognized welfare burden for horses. Continuous fly harassment prevents normal resting and grazing behavior - horses spending large proportions of their day stamping, tail swishing, head tossing, and seeking shelter from insects are experiencing real welfare compromise. Face flies that feed on eye and nasal secretions cause irritation that can lead to eye infections and painful periorbital lesions. Bot fly eggs laid on legs produce skin irritation when horses lick them, and the larvae cause gastric damage internally. Stable flies bite to blood-feed, causing pain and distress. The cumulative welfare impact of uncontrolled insect burden through summer is substantial, and owners who implement effective fly control provide meaningful welfare improvements for horses in their care.