USDA to Reopen Southern Cattle Ports August 24 After Screwworm Closure

The phased reopening signals the USDA's assessment that containment measures have sufficiently reduced screwworm risk, though the agency has not declared the outbreak fully eradicated.

The U.S. Department of Agriculture announced Friday, July 25, 2026, that it will begin a phased reopening of southern livestock ports closed in May 2026 following the detection of New World Screwworm (NWS) in cattle crossing from Mexico. The first port scheduled to reopen is Douglas, Arizona, with operations set to resume on August 24, 2026, according to the USDA announcement reported by The Hill.

The livestock ports were shut down in May 2026 after USDA inspectors confirmed NWS presence in cattle imported through the southern border crossings. New World Screwworm, or Cochliomyia hominivorax, is a parasitic fly whose larvae infest the living tissue of warm-blooded animals and can cause severe economic losses to the U.S. cattle industry. The United States had previously eradicated NWS domestically through a decades-long USDA sterile insect technique program, making any reintroduction a regulatory priority. The USDA has not publicly stated in the July 25 announcement that the outbreak has been fully eradicated on the Mexican side of the border.

The Douglas, Arizona port is the first of at least three ports identified for phased reopening, according to The Hill's report citing the USDA announcement. The agency did not specify in the initial announcement the dates or sequence for reopening the remaining two ports. The phased approach indicates the agency intends to monitor conditions at each crossing before expanding the policy across additional entry points.

The cattle import closure carried measurable economic implications for U.S. feedlot and processing operations that depend on Mexican feeder cattle. The full volume of cattle trade interrupted by the May closure and the cumulative economic impact on U.S. livestock markets since that date are not specified in the USDA announcement reviewed for this report. Those figures would be available through USDA's Agricultural Marketing Service weekly livestock import data, which is publicly accessible at ams.usda.gov.

What remains unknown includes the specific containment milestones the USDA required before authorizing the phased reopening, whether Mexico's Secretaría de Agricultura y Desarrollo Rural (SADER) formally certified reduced NWS activity, and the inspection protocols that will govern cattle movement once Douglas reopens on August 24. The USDA's Animal and Plant Health Inspection Service (APHIS) maintains public records of NWS program activities and any formal bilateral agreements with Mexican agricultural authorities would be filed with APHIS and potentially subject to disclosure under the Freedom of Information Act.