Mexico resumes limited cattle exports to US after two-year screwworm ban

Live cattle exports from Mexico to the United States resumed on Monday, nearly two years after they were suspended due to a screwworm outbreak. The first crossings took place in the afternoon at the border town of Agua Prieta in Sonora, with animals moving into Douglas, Arizona, after hours of joint inspections by Mexican and American authorities.

Inspectors used dogs to check each animal for signs of the parasitic larvae, which are deposited by the Cochliomyia hominivorax fly. The pest invades open wounds or mucous membranes of warm-blooded animals, including humans, and feeds on living tissue, causing deep and painful lesions.

The outbreak was first detected in Mexico in November 2024 and has since spread to 30 of the country's 32 states, including Sonora. In the United States, cases began appearing in Texas and New Mexico in June. Mexico currently reports 1,937 active cases of the infestation.

To restart trade, the U.S. approved a new protocol requiring radio-frequency identification tags in the ears of cattle and the installation of scanners at border points to verify the tags. Crossings are capped at 700 head per day initially, rising to 900 next week and 1,300 the following week.

Mexican President Claudia Sheinbaum welcomed the reopening and outlined measures to contain the outbreak, including stronger cattle tracing systems and continued release of sterile flies in border states such as Sonora and Chihuahua, which are the largest exporters of cattle to the U.S.

While the resumption brings relief to ranchers who suffered heavy losses during the ban, the strict limits will slow the recovery of the industry. U.S. herds are at their lowest levels in 75 years, with a shortfall of about 1.2 million cows, contributing to higher beef prices.