--- title: The Cattle Border Reopens on August 24 With 23 Texas Counties Still Under Screwworm Orders description: The US resumes limited Mexican cattle imports on August 24 while 23 Texas counties stay under New World screwworm movement orders. author: Darie Nani (Editor-in-Chief) updated: 2026-08-08T01:22:41.926Z canonical: https://www.sovereignmagazine.com/article/cattle-border-reopens-texas-screwworm-orders categories: Supply Chains content_type: News region: United States publication: Sovereign Magazine schema_type: Article --- The United States will resume limited imports of Mexican cattle on August 24, reopening a trade route that has been shut for more than a year, while 23 Texas counties stay under movement restriction because of an active New World screwworm zone. USDA says the first shipments will cross at Douglas, Arizona, opposite Agua Prieta, Sonora, with every animal inspected by US officials before entry. The agency can pause the trade again if surveillance shows the parasite spreading or safeguards slipping. ## The US Cattle Herd Was Already the Smallest in Decades The reopening lands on an industry short of animals. USDA counted 86.2 million head of cattle nationwide on January 1, the lowest figure in decades, with cattle on feed down 3% from a year earlier. Drought, high feed costs and years of herd liquidation had tightened supply and [pushed beef prices to record levels](https://www.sovereignmagazine.com/article/three-shocks-behind-us-inflation-daly-tokyo) before screwworm reached Texas. Mexico supplied more than 1 million cattle a year, many of them calves bound for US feeding operations, before the border closed. Texas alone counted 12.1 million cattle and calves at the start of the year, about 14% of the national herd. ## Texas Requires a Certificate for Every Animal Leaving the Zone New World screwworm was confirmed on June 3 in a calf in Zavala County. The calf has recovered and that individual case is now inactive, but the [Texas Animal Health Commission keeps an established infested zone across parts of the Hill Country and the border counties](https://www.tahc.texas.gov/emergency/nws.html). Under orders from the commission's executive director, no warm-blooded animal may leave the zone without prior authorization. A commission official or a certified screwworm inspector must examine the animal and complete a movement and treatment certificate naming the product used for prevention or treatment and the animal's official identification, and that certificate has to travel with the animal. The commission has issued and modified the orders repeatedly since June 9, with the most recent, covering Pecos and Terrell counties, dated August 5. ## The Parasite Moved North From Central America Before It Reached Texas Cases in Central America climbed quickly from 2023, spreading to Costa Rica, Nicaragua, Honduras, Guatemala, Belize and El Salvador. Screwworm was detected in a cow at a Mexican inspection checkpoint in Chiapas in November 2024, and its spread north through Mexico has been confirmed since. Screwworm larvae feed on living tissue, unlike most fly species found in wounds, which feed on dead tissue and fluids, and an untreated infestation can kill the animal. The United States last eradicated the parasite in 1966 using the sterile insect technique, and that method is running again in the affected areas. Sterilized male flies are released by ground and by air. A female mates only once in her life, so the ones that mate with a sterile male lay eggs that never hatch, and the population falls over several life cycles. ## USDA Ties Each Shipment to Mexico's Pest Control Compliance Mexican President Claudia Sheinbaum announced the reopening after receiving a letter from US Agriculture Secretary Brooke Rollins, calling it "great news for Mexican ranchers". Exports will begin through Sonora before expanding to Chihuahua, where Sheinbaum said five screwworm cases were recently reported, and Mexico says it will keep working with US authorities and with its own agricultural health agency, SENASICA. The Santa Teresa and Columbus crossings in New Mexico, which would restore access for Chihuahua cattle, are expected to reopen later, though USDA has not set dates. Continued access depends on Mexico holding to the joint pest control measures the two governments agreed. ## Producers Are Split Over Whether the Reopening Comes Too Soon Texas Agriculture Commissioner Sid Miller welcomed the limited resumption but said the prolonged closure had already disrupted producers and supply chains in the state. State officials estimate a major outbreak could cost Texas cattle producers $732 million a year and cut statewide economic activity by $1.8 billion. Feedlots in Texas, Oklahoma and New Mexico have argued that imports can restart safely under strict inspection protocols and would help packers meet demand. Some cattle groups remain opposed, warning that renewed movement could raise the risk of further infestation. ## An Emergency Authorization Clears a Wound Spray for Prevention Only Elanco Animal Health says it received an Emergency Use Authorization from the FDA on August 7 for CLiK Extra, a topical wound spray meant to prevent screwworm infestation in cattle, sheep, goats, swine, camelids and several wildlife species. The company says the product is not approved to treat an infestation already under way, and a wound that becomes infested after treatment needs something else. Two other Elanco products, Negasunt Powder and Tanidil, received emergency authorizations earlier in the year and reach producers only through USDA's Animal and Plant Health Inspection Service, in coordination with state officials and federally recognized tribal agencies. > "Education is a producer's most powerful tool in this fight." > — Dr M. Wayne Ayers, Senior Technical Consultant, Elanco Ayers says the practical defence is inspection and speed: checking animals as often as possible, treating any noticeable lesion or sore, and catching an infestation before the next generation of flies completes its life cycle. ## FAQ **Q: Can screwworm infect humans?** Yes. The Texas Animal Health Commission says the parasite primarily infests livestock but can also affect other mammals, including humans, and birds, by laying eggs in open wounds or body orifices. **Q: Is it safe to eat beef during the outbreak?** USDA's Food Safety and Inspection Service inspects the commercial meat supply, and any evidence of screwworm infestation would be identified in that process. Adulterated product from an affected animal is not allowed into commerce. **Q: Which US states have confirmed screwworm?** Screwworm was confirmed in Texas and in southeastern New Mexico in June. The Texas infested zone now covers parts of 23 counties, chiefly in the Hill Country and along the Rio Grande. **Q: How is New World screwworm eradicated?** The United States eliminated it in 1966 using the sterile insect technique, which is running again now. Sterilized males are released so that females who mate with them lay eggs that cannot hatch, reducing the population over successive generations. **Q: What does the movement order actually require of a rancher?** An animal leaving the infested zone needs prior authorization from the Texas Animal Health Commission, an inspection by the commission or a certified screwworm inspector, and a movement and treatment certificate that travels with it.