Agriculture Secretary Russell Redding issued a quarantine order limiting animal movements and urged Pennsylvania farmers and pet owners to tighten biosecurity to protect their livestock and pets following heightened risks of New World Screwworm following confirmed cases in Texas and New Mexico.
“Pennsylvania has no confirmed cases of New World Screwworm, but this destructive pest poses a serious threat to our livestock industry, companion animals, wildlife, and agricultural economy,” Sec. Redding said. “Taking proactive steps now to strengthen biosecurity and limit unnecessary animal movements from affected areas will help protect our farms and communities.”
On June 3, the U.S. Department of Agriculture confirmed the first U.S. case of NWS in Texas. As of June 10, additional cases were reported with four more across Zavala, Gillespie, and LaSalle Counties in Texas, as well as one case in Lea County, New Mexico.
NWS is a devastating pest. When NWS fly larvae – maggots – burrow into the flesh of a living animal, they cause serious, often deadly damage. NWS can infest livestock, pets, wildlife, occasionally birds, and in rare cases, people.
“New World Screwworm is unlike the flies and maggots we commonly encounter,” State Veterinarian Dr. Alex Hamberg said. “These larvae feed on living tissue, causing severe wounds that can quickly become life-threatening if left untreated. Producers, veterinarians, and pet owners should regularly inspect animals for wounds that fail to heal or show signs of maggot infestation. If producers suspect NWS, they should seek veterinary care immediately.”
Movement controls, early detection, and rapid reporting are critical to keeping this pest out of Pennsylvania and safeguarding the health of our animals. The Pennsylvania Department of Agriculture will continue to provide community outreach and education to help detect this threat.
Pennsylvania’s quarantine order, which took effect on June 9, establishes movement restrictions and enhanced animal health requirements for susceptible domestic animals entering Pennsylvania from affected areas. The order includes provisions for veterinary inspection, animal health certification, and preventative measures designed to reduce the risk of NWS entering the Commonwealth through animal movements.
Animal owners, producers, veterinarians, transporters, and others moving susceptible animals should consult the quarantine order and work with state or federal animal health officials to ensure all applicable requirements are met before movement.
While the risk to human health is low, the Department of Agriculture is working in full coordination with the Pennsylvania Department of Health, Pennsylvania Game Commission, and the Department of Environmental Protection to mitigate risks.
The Department of Agriculture has continued to highlight the necessity of strict adherence to farm-specific biosecurity plans and vigilance.
Pennsylvanians are advised to monitor their livestock and pets for the signs such as irritated behavior, head shaking, the smell of decay, and the presence of maggots in wounds.
Adult screwworm flies are about the size of a common housefly or slightly larger. They have orange eyes, a metallic blue or green body, and three dark stripes along their backs.
NWS is not an environmental maggot. The larvae develop only in the living tissue of warm-blooded animals, typically entering through an open wound or ulceration or tear in the skin or mucous membranes.
Anyone who suspects an NWS infestation should immediately contact their veterinarian and report the suspected case to the Pennsylvania Department of Agriculture’s Bureau of Animal Health and Diagnostic Services at (717) 772-2852. Prompt reporting is essential to protect Pennsylvania’s livestock, pets, and wildlife.
