U.S. halts Mexican cattle imports as flesh-eating parasite surges north-$119M trade at stake.
EXECUTIVE SUMMARY: The USDA suspended all live cattle, horse, and bison imports from Mexico on May 12, 2025, after detecting the deadly New World Screwworm (NWS) 700 miles from the U.S. border. This flesh-eating parasite, eradicated in the 1960s, now threatens to destabilize North American livestock markets, with Mexican cattle exports plummeting 79% pre-ban. Despite a brief February 2025 trade resumption, failed containment protocols and diplomatic tensions over sterile fly releases forced drastic action. U.S. industry groups back the move, prioritizing biosecurity over immediate economic pain, while Mexico faces mounting pressure to prove eradication progress. A 1976-style outbreak could cost Texas .8B today-risks outweigh short-term trade losses.
KEY TAKEAWAYS
- Border shutdown bites: Immediate halt to 1.25M annual Mexican cattle imports disrupts feedlots and risks U.S. beef price hikes.
- Parasite peril: NWS kills cattle in 1-2 weeks, spreads via wildlife, and breached containment zones despite sterile fly tech.
- $1.8B nightmare: A single Texas outbreak could match 1976’s devastation-prevention saves $1B/year in control costs.
- Industry backs ban: NCBA calls it “necessary pain” to protect herds, blaming Mexico’s delayed response.
- No quick fix: Trade resumption requires Mexico to prove sustained containment-outlook uncertain.
The U.S. Department of Agriculture has suspended all imports of live cattle, horses, and bison from Mexico, effective immediately. This decisive action announced May 12, 2025, by Agriculture Secretary Brooke Rollins, comes in response to the alarming northward spread of New World Screwworm (NWS). This devastating parasite eats animals alive.
The suspension, implemented on a month-by-month review basis, marks a critical biosecurity response to recent detections of screwworm in Mexico’s Oaxaca and Veracruz regions – approximately 700 miles from the U.S. border. This border shutdown creates immediate supply chain disruptions for dairy producers while raising urgent questions about biosecurity vulnerabilities across the industry.
“The protection of our animals and safety of our nation’s food supply is a national security issue of the utmost importance,” Rollins stated, emphasizing that the decision represents a safety measure rather than political action against Mexico.
Why This Parasite Terrifies Agriculture Officials
The New World Screwworm isn’t your typical farm pest – it’s agricultural nightmare fuel. Unlike common flies, NWS larvae actively burrow into and consume the living flesh of warm-blooded animals, creating expanding wounds that rapidly become infected.
The parasites typically kill adult cattle without treatment within 1-2 weeks. What makes this threat particularly concerning is its indiscriminate appetite – it targets virtually any warm-blooded animal, including livestock, wildlife, pets, and occasionally humans.
The graphic nature of these infestations – flesh-eating maggots that can kill even large animals rapidly – explains why agricultural officials react decisively when detecting this pest.
Economic Shockwaves for Dairy Operations
This isn’t just about beef cattle. The import suspension creates immediate ripple effects throughout North American supply chains that directly impact dairy operations.
Mexico traditionally ranks as one of the largest suppliers of live cattle to the United States. In 2024, U.S. imports from Mexico reached 1.25 million head of cattle, valued at approximately 9.27 million and representing about 4% of total U.S. cattle slaughter.
This disruption comes at a particularly challenging time for dairy producers, as the U.S. cattle industry already faces tight supplies due to a historically small domestic herd. The USDA had forecast an 8% rise in feeder steer prices for 2025 before this development – a trend likely to accelerate with the import ban.
A Hard-Earned Victory at Risk
This situation particularly frustrating because we’ve beaten this enemy before. The U.S. and Mexico successfully eradicated screwworm in the 1960s and ’70s through an innovative approach called Sterile Insect Technique (SIT).
This method involves releasing millions of radiation-sterilized male flies that mate with females but produce no offspring, eventually collapsing wild populations. This historic campaign created a “barrier zone” that kept the pest from encroaching northward.
However, the parasite has broken through containment barriers in Central America in recent years and progressively moved northward. The current crisis represents the potential unraveling of decades of successful pest exclusion.
The Failed Protocols and Diplomatic Tensions
This May suspension represents a crucial reversal of policy. After initially detecting NWS in southern Mexico in November 2024, the U.S. implemented an import ban that was lifted in February 2025 when both countries agreed on enhanced inspection protocols.
The recent northward progression of NWS demonstrates that these measures failed to contain the threat.
Behind the scenes, significant tensions emerged in the binational response. U.S. officials voiced concerns that Mexican authorities were impeding crucial SIT operations by denying landing permissions for specialized aircraft, creating paperwork issues, imposing substantial customs duties on eradication equipment, and limiting necessary flight operations.
Industry Perspectives: Necessary Protection or Excessive Response?
The USDA’s decision has garnered strong support from major U.S. cattle industry organizations despite acknowledging the economic hardship it creates.
NCBA CEO Colin Woodall asserted that the “USDA’s border closure was entirely avoidable,” blaming “unnecessary bureaucratic hurdles” and a “lack of timely action by officials in Mexico” for allowing NWS to spread unchecked.
Mexico’s Agriculture Secretary Berdegué expressed disagreement with the suspension measure, though he remained optimistic about reaching a swift resolution through continued dialogue.
What Happens Next?
The import suspension will continue month by month until Mexico demonstrates “a significant window of containment” through increased surveillance and successful eradication efforts.
Given the extent of the NWS spread and the historical complexity of eradication campaigns, achieving the required containment level may be a lengthy process. Some U.S. stakeholders have stated that the ultimate goal should be pushing the NWS infestation south of Panama’s Darien Gap.
This prolonged uncertainty could potentially force North American livestock flows to restructure, creating lasting shifts in pricing patterns and supply relationships.
The Bottom Line: What Dairy Producers Need to Know
For dairy operations across North America, the NWS crisis creates multiple layers of concern that demand attention:
- Economics: With Mexican cattle imports suspended, expect continued upward pressure on feeder and cull cattle prices. This shifts profitability equations for dairy operations when marketing cull cows and male calves.
- Biosecurity Imperatives: The rapid spread of NWS is a stark reminder that robust on-farm biosecurity isn’t optional. One case could trigger extensive quarantines affecting entire regions.
- Broader Market Disruption: A prolonged trade suspension will likely force North American livestock flows to restructure, potentially creating lasting shifts in pricing patterns and supply relationships.
- Lessons in Crisis Management: The failure of initially agreed protocols demonstrates that partial measures against severe biological threats often prove inadequate. When facing potential catastrophic outcomes, decisive action becomes necessary despite immediate economic pain.
The best-case scenario involves Mexico rapidly implementing effective containment measures, allowing trade to resume within months. The worst-case scenario – an established NWS population in the U.S. – would trigger massive eradication costs and potential dairy herd losses.
For forward-thinking dairy producers, this situation demands monitoring developments along the southern border while assessing your operation’s vulnerability to supply chain disruptions and potential biosecurity threats. In today’s interconnected global dairy industry, threats can emerge rapidly from unexpected directions, and preparation remains your best defense.
Learn more:
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