The Pennsylvania Department of Agriculture has implemented a mandatory quarantine for susceptible domestic animals entering the state, citing a rise in confirmed New World screwworm cases in Texas and New Mexico. As of June 10, the U.S. Department of Agriculture reports that the parasite—which feeds on living tissue—has moved into multiple counties, though no cases have been identified in Pennsylvania. The order requires strict veterinary inspections and health certifications for all animal transport to prevent the establishment of this destructive pest in the state’s agricultural sector.
Why is the New World screwworm a threat to livestock?
Unlike common housefly larvae that feed on decaying matter, the New World screwworm (NWS) exclusively consumes the living flesh of warm-blooded animals. According to Pennsylvania State Veterinarian Dr. Alex Hamberg, these larvae create deep, rapidly expanding wounds that can become fatal if left untreated. Because the pest can infest livestock, pets, wildlife, and even humans, state officials are prioritizing early detection to prevent the widespread economic damage historically associated with this parasite.
What does the Pennsylvania quarantine order require?
The quarantine, which took effect June 9, places strict limits on the movement of susceptible animals entering Pennsylvania from regions where the screwworm has been identified. According to the Pennsylvania Department of Agriculture, transporters and owners must comply with the following:
- Veterinary Inspections: Animals must be examined by a licensed veterinarian before being cleared for transport.
- Health Certification: Official documentation must verify the animal’s health status and origin.
- Preventive Measures: Transporters must follow state-mandated protocols to reduce the risk of introducing the parasite into local herds.
State officials urge producers to coordinate with the Bureau of Animal Health and Diagnostic Services at 717-772-2852 before moving any livestock into the commonwealth.
How to identify a New World screwworm infestation
Recognizing the adult fly and the signs of infestation is the first line of defense for farmers and pet owners. The adult screwworm fly is slightly larger than a common housefly, featuring orange eyes, a metallic blue or green body, and three distinct dark stripes on its back. If the larvae have already entered an animal, look for these clinical signs:
- Persistent, unusual irritation or head shaking.
- A distinct smell of decay emanating from a wound.
- Visible maggot activity within an open sore or skin tear.
Future trends in biosecurity and livestock protection
The current outbreak in Texas and New Mexico highlights a growing need for regional biosecurity coordination. Pennsylvania is currently partnering with the Department of Health, the Pennsylvania Game Commission, and the Department of Environmental Protection to monitor potential entry points. Industry experts suggest that as climate patterns shift, the geographic range of warm-weather pests like the screwworm may expand, forcing states to move from reactive containment to permanent, high-standard inspection protocols for interstate animal commerce.
Frequently Asked Questions
Is the New World screwworm currently in Pennsylvania?
No. As of mid-June, there have been no confirmed cases of New World screwworm in Pennsylvania, according to the state’s agriculture department.
What should I do if I suspect an infestation?
Do not attempt to treat the animal yourself. Contact your veterinarian immediately and report your suspicions to the Pennsylvania Bureau of Animal Health and Diagnostic Services at 717-772-2852.
Can this pest affect my dog or cat?
Yes. The New World screwworm can infest any warm-blooded animal, including companion pets, wildlife, and occasionally humans.
Stay informed on regional agricultural health alerts by subscribing to our biosecurity newsletter or checking the Pennsylvania Department of Agriculture website for real-time updates. Have you adjusted your farm’s transport protocols? Share your thoughts in the comments below.