New World screwworm in livestock production systems: biosecurity, economic considerations, and management for cattle, sheep, goat, horse, and swine producers

New World screwworm (Cochliomyia hominivorax) is a transboundary obligate myiasis-causing parasite that poses serious threats to livestock production through infestation of living tissue, rapid lesion progression, animal suffering, and substantial economic loss. Between June 3 and June 16, 2026, the US confirmed 12 cases of New World screwworm in domestic animals across Texas and New Mexico, marking the first detections in production livestock in the continental US since 1966. Cases have involved cattle, sheep, goats, and a dog across multiple counties, with all 12 classified as active and no wild fly trap detections recorded as of the manuscript preparation date. This narrative review synthesizes current producer-facing evidence on production-level risk factors, herd and flock biosecurity, species-specific vulnerabilities, surveillance and reporting pathways, and the economic and trade implications of an active outbreak. Practical prevention measures examined include timing invasive husbandry procedures to low-risk periods, strengthening wound prevention and inspection protocols, and improving sanitation for vehicles, equipment, and personnel. Population-level control strategies (principally the sterile insect technique, now deployed via aerial and ground releases in and around the detection zone) and current regulatory responses, including multiple FDA emergency-use authorizations for animal drugs, are summarized to support preparedness planning across livestock systems. The principal contribution of this review is to reframe the producer and veterinary response to screwworm from individual-animal treatment to production-system prevention, consolidating 2023 to 2026 guidance from USDA, FDA, AVMA, and cooperative extension programs into a practical roadmap for reducing risk, preserving animal welfare, and protecting market access at the herd and flock level.