New Mexico Border Crossing Reopens After Two-Year Closure Due to Screwworm

The border crossing at Columbus, New Mexico, has reopened to Mexican cattle after a nearly two-year closure aimed at containing the spread of the New World screwworm, a parasitic fly larva that infests livestock. The reopening on Monday follows enhanced inspection and treatment protocols implemented by both U.S. and Mexican authorities.

The screwworm poses a significant threat to the U.S. cattle industry, valued at $113 billion, and its containment efforts have impacted trade and jobs in border communities. The closure also limited the U.S.'s ability to import cattle to rebuild drought-depleted herds, though officials caution that consumers should not expect immediate changes in beef prices.

Under new safeguards, cattle undergo rigorous testing, vaccination, and inspection before reaching the border. This multi-layered approach is designed to instill confidence that imported animals will not carry the parasite. However, vigilance remains crucial, as flies can cross the border independently, necessitating continued caution from ranchers, hunters, and pet owners.

The New World screwworm, once a common annual threat, was largely eradicated in the U.S. by the 1960s. It reappeared in Mexico in 2024, with the first confirmed U.S. case reported in Texas in June. Since then, more than 60 cases have been documented in Texas and New Mexico, affecting cattle, sheep, goats, horses, and dogs. A recent confirmed case in an elk marked the first instance in U.S. wildlife.

Before the current outbreak, the U.S. imported approximately one million head of cattle annually. Dudley Hoskins, undersecretary for the Department of Agriculture, stated that while the goal is to return to previous import levels, it will be a gradual process managed with strict attention to animal health risks. "As long as we can manage and mitigate that risk at an acceptable level, we will continue to process the safe and legal movement of cattle through these ports," Hoskins said.

Columbus and the Santa Teresa port near El Paso, Texas, typically handle about one-third of all Mexican cattle imported into the U.S. each year, representing an estimated $1 billion in trade for the region, according to Gerardo Fierro, executive director of the New Mexico Border Authority. The closure had led to a loss of jobs, reduced cattle sales, and decreased tax revenue, impacting local businesses that supplied ranchers.

Another cattle crossing in Arizona is scheduled to reopen by late November. State veterinarian Samantha Holeck detailed the extensive preparation process for imported cattle, which begins at ranches with private veterinarians administering preventative treatments and checking for other diseases. Accredited veterinarians in Mexico conduct further inspections for open wounds or signs of illness before USDA officials perform a final head-to-tail inspection.

Cattle also undergo an insecticide dip to eliminate any remaining parasites. The USDA is employing fly traps and drones for aerial surveys to monitor screwworm populations. A significant part of the containment strategy involves a program to breed and release sterile male flies from aircraft, which mate with wild females, thereby interrupting the life cycle. A new $610 million facility in Texas will bolster production of sterile flies, complementing existing operations in Mexico and Panama.

While the reopening provides a vital market for Mexican feeder cattle, experts note that U.S. ranchers face a lengthy recovery period to rebuild herds affected by years of drought. This constrained supply has contributed to increased cattle prices.