Heavy external parasite burdens including lice, mange mites, and flies cause chronic irritation and blood loss in cattle that impair welfare and production, yet are frequently undertreated in extensive beef systems.
External parasites cause chronic discomfort rather than acute pain — itching, irritation, and blood loss that affect behavior and condition progressively. Cattle under heavy fly pressure lose significant daily grazing time through defensive behaviors, creating both welfare and production costs. The chronic nature of parasite-induced discomfort means it often receives less attention than acute illness, despite causing substantial ongoing welfare harm in undertreated populations.