Following a closure of more than one year driven by New World screwworm (NWS) concerns, the United States border has reopened to live cattle imports from Mexico. USDA Under Secretary for Marketing and Regulatory Programs Dudley Hoskins recently led a delegation to the port in Douglas, Arizona, alongside Acting Chief Veterinary Officer Alan Huddleston, to mark the resumption of trade under comprehensive animal health safeguards. Rod Bain and USDA officials share the steps within this protocol in this edition of “Agriculture USA”.
Hoskins affirmed that every measure implemented at the Douglas port is designed around animal health for domestic producers, noting that the agency stands fully behind both the protocol and the system.
To prevent NWS from entering the country and posing a risk to livestock and domestic pets, USDA established a strict, three-stage prevention protocol outlined by Dr. Huddleston.
Stage One: Origin and Export Gathering Centers The initial phase begins in Mexico at the farms of origin or export gathering centers. Within 30 days prior to movement, an authorized, accredited veterinarian conducts a thorough inspection to ensure animals exhibit no signs of disease, specifically New World screwworm infestation. Between 7 and 14 days before transit, cattle receive a tick treatment, followed by a targeted product administered 3 to 5 days before departure that treats and prevents NWS. Once cleared, an international health certificate is issued to permit movement.
Stage Two: Pre-Export Inspection Stage two occurs just across the border at Mexican pre-export facilities. An official veterinarian from the Mexican Department of Agriculture conducts a second physical inspection 24 hours prior to crossing, confirming animals remain free of NWS signs. At this point, official animal identification and records are coordinated for traceability.
Stage Three: Port of Entry and Clearance The final phase takes place at USDA Animal and Plant Health Inspection Service (APHIS) facilities in Mexico before cattle cross into the United States. During transport into the facility, detector dog teams screen the cattle, scenting for wounds or NWS larvae and signaling handlers if suspicion arises. An APHIS animal health technician performs a third physical examination and verifies that electronic identification is readable for traceback capabilities. The cattle then pass through a treatment vat targeting screwworm and any other hide pests. Once dried, the animals cross into Douglas, where they are grouped into lots for buyers and shipped to their destination points within the country.
Huddleston cautioned that finding NWS at any point in this system triggers strict protocols: the affected lot is denied entry into the United States. If detected as animals arrive at the APHIS facility, all exports halt, the cattle are returned to their farms of origin, and the port shuts down for full premises cleaning and disinfestation.
