Minnesota health officials are urging livestock producers and pet owners to remain highly vigilant following warnings that the destructive New World screwworm could inadvertently be introduced into the state. State Veterinarian Dr. Brian Hoefs expressed deep concern that the flesh-eating parasite, which was recently detected in livestock and companion animals across Texas and New Mexico, could travel north via cross-border commerce and vacationing families traveling with their dogs. While the federal government has historically maintained a strict biological barrier against the pest, its sudden resurgence in the American Southwest has put northern agricultural sectors on high alert.
Unlike native fly species whose maggots feed exclusively on dead tissue, the New World screwworm fly lays its eggs in open wounds or body orifices of live, warm-blooded animals. Once the eggs hatch, the screw-shaped larvae aggressively burrow into healthy flesh, devouring the host from the inside out and creating severe, expanding lesions. Hoefs noted that while the risk of the parasite establishing a permanent, ongoing population in the Upper Midwest is almost nonexistent due to freezing winter temperatures, Minnesota’s hot summer months provide the perfect environment for the fly to rapidly complete its two-to-three-week life cycle and wreak short-term havoc on local herds.
To counter the looming biosecurity threat, the U.S. Department of Agriculture (USDA) recently approved a specialized research proposal submitted by the Minnesota Board of Animal Health. The state-led initiative will focus on designing and piloting practical screening, triage, and referral protocols for animals arriving from high-risk or endemic zones. Concurrently, political leaders are pushing for federal reinforcements; Minnesota Senator Amy Klobuchar recently called on the federal government to aggressively hire more agricultural veterinarians to enhance domestic livestock inspections and suppress the outbreak before it exerts upward price pressure on the commercial beef industry.
State authorities emphasize that compliance with existing certificates of veterinary inspection remains the most effective defense line for cattle and swine producers. However, companion animal travel poses an equal risk, prompting the Board of Animal Health to instruct residents returning from southern states to meticulously inspect their pets for abnormal skin openings, foul-smelling wounds, or unusual lethargy. If an infestation is suspected, veterinarians and owners are legally required to report the case immediately to state regulators to ensure localized containment and protect the regional livestock economy.
