MEXICO CITY (RFD-TV) — A new livestock checkpoint in Montemorelos, Nuevo León, stopped a calf carrying New World screwworm—and the larvae were already dead.
Under Mexico’s reinforced rules, all animals receive a double treatment (ivermectin plus a larvicidal bath). Inspectors treated and checked the full load of 85 head and found no other cases.
This most recent case was discovered 170 miles south of the border, in a shipment of more than 80 animals. Mexico’s ag ministry says this was the second confirmation in two weeks.
The infected animal was a calf, but no other livestock was infected with screwworm. Mexican officials say that when the pest was discovered, it was already dead, primarily due to mandatory treatments in Mexico.
A detection was reported last month, located closer to the US, just 70 miles south of the Texas border. Officials said this incident is separate from the Sept. 20 detection in Sabinas Hidalgo, which was officially declared inactive on Oct. 5 after tracing, wound care for thousands of animals, trapping, and sterile-fly releases.
Farm-Level Takeaway: Border controls and mandatory treatments in Mexico, plus a new U.S. tool (Dectomax-CA1), are tightening the net on screwworm. Mexico’s tougher, two-step treatment and added checkpoints are catching cases before they can spread—good news for producers near the border.
On the U.S. side, regulators have conditionally approved Dectomax-CA1 (doramectin injection) for the prevention and treatment of screwworm in cattle, with 21 days of reinfestation protection. The move is meant to get producers a tool now while full-effectiveness data are finalized. Label restrictions and withdrawal times still apply, and veterinarians are urging the targeted use of these products as part of an integrated parasite control plan to help prevent animals from developing resistance to treatments.
Agriculture Secretary Brooke Rollins says she has been in touch with Mexican officials. As a result of this latest detection, the USDA will send crews to the region to deploy traps and release more sterile flies. Rollins says the USDA’s number one goal remains keeping the U.S. herd safe and secure.
USMEF President and CEO Dan Halstrom shares how recent trade talks are influencing U.S. red meat global sales and the importance of key trade agreements like the USMCA.
November 12, 2025 03:07 PM
·
Winter weather will challenge livestock producers working to rebuild their herds despite harsh conditions.
November 12, 2025 01:20 PM
·
Enforceable origin labels could create clearer premiums for U.S. cattle and address concerns some producers have had with competition from foreign imported beef.
November 12, 2025 12:39 PM
·
The National Milk Producers Federation (NMPF) says recent wins in markets like Malaysia and Cambodia help farmers focus on production rather than trade barriers.
November 11, 2025 03:50 PM
·
Lucia Ruano, USMEF’s Central America representative, discusses what is driving demand for U.S. beef and pork in the region.
November 11, 2025 01:30 PM
·
Tyson expects another year of beef-segment losses due to tight cattle supplies, even as chicken, pork, and prepared foods strengthen overall margins.
November 11, 2025 01:26 PM
·
A smaller U.S. turkey flock and resurgent avian flu have tightened supplies, driving prices higher even as other key holiday foods show mixed trends.
November 10, 2025 03:05 PM
·
The DOJ’s new antitrust probe could reshape beef-packer behavior, with potential impacts on fed-cattle prices, processor margins, and long-term competition across the supply chain.
November 10, 2025 10:35 AM
·
Verified U.S. data show real leather’s carbon footprint is lower than advertised — an edge for the American cattle industry in both marketing and byproduct value.
November 07, 2025 11:32 AM
·
