Screwworm 2025: Economic Risks, Outbreak Updates, and How Farmers Can Protect Livestock

 Screwworm 2025: Economic Risks, Outbreak Updates, and How Farmers Can Protect Livestock

Introduction

In 2025, a small parasite is making big news across the livestock industry—the screwworm. Known scientifically as Cochliomyia hominivorax, this flesh-eating fly lays its eggs in open wounds of animals. Once hatched, the larvae burrow into living tissue, causing painful infections that can lead to death if untreated.

After decades of being eradicated from the United States, screwworms are once again creeping closer to the border. For farmers, ranchers, and policymakers, this is more than a veterinary issue—it’s an economic risk that could shake the entire beef industry.

What Is the Screwworm and Why Is It Dangerous?

Screwworms are not ordinary pests. Unlike common maggots that feed on dead tissue, screwworm larvae consume living flesh. This makes infestations deadly for cattle, horses, sheep, goats, wildlife, pets, and even humans.

A single untreated wound can host thousands of larvae. Infected animals become weak, lose weight rapidly, and in severe cases, die. The loss isn’t just emotional for farmers—it’s financial, cutting into herds and profits.

Outbreak Updates: Where Screwworms Are Spreading in 2025

In late 2024, screwworm cases surged in southern Mexico.

By mid-2025, the parasite had advanced nearly 400 miles north, sparking urgent containment efforts at the U.S.–Mexico border.

The USDA confirmed that the first U.S. human case in decades was identified in Maryland in August 2025, traced back to a traveler returning from Guatemala.

Wildlife in Texas and New Mexico are under close surveillance, with ranchers urged to monitor cattle daily.

This northward spread is the fastest since the 1970s, raising alarms about a possible re-establishment of screwworms in U.S. cattle country.

The Economic Risks of a Screwworm Outbreak

The financial threat of a screwworm invasion cannot be overstated.

1. Cost to Farmers

According to USDA estimates, if screwworms were to re-enter Texas:

$732 million in losses could hit livestock producers in a single year.

Ranchers would face higher medical costs, reduced productivity, and animal deaths.

2. Statewide Economic Impact

When adjusting historical outbreak costs to today’s values, the total loss to the Texas economy could reach $1.8 billion. That includes lost jobs, reduced beef exports, and disruptions in rural communities that rely heavily on cattle.

3. National Market Disruption

Beef futures and cattle prices are already sensitive to supply chain shocks. A widespread outbreak could:

Increase beef prices for consumers.

Trigger feedlot shortages.

Reduce U.S. beef exports, especially to countries with strict health requirements.

How Authorities Are Responding

To protect livestock and the economy, U.S. agencies are mobilizing resources quickly.

Emergency Funding

In late 2024, the USDA released $165 million in emergency funding for surveillance and control measures in Central America and along the border.

Import Bans

Live cattle imports from Mexico were temporarily halted in 2025 to limit the risk of infected animals entering the U.S.

Sterile Insect Technique (SIT)

The USDA is building a $750 million sterile-fly production facility in Texas.

This facility will be capable of producing 300 million sterile screwworm flies each week, which will be released to compete with wild populations and break their reproductive cycle.

Additional support comes from plants in Mexico and Panama, creating a regional shield against outbreaks.

Veterinary Tools

The FDA has authorized emergency use of certain animal drugs, like ivermectin, to help treat and prevent infestations.

Veterinarians have been trained to recognize early symptoms and respond quickly.

Border Patrols and Surveillance

“Tick Riders” patrol the border on horseback, monitoring herds for signs of infection.

Detection dogs are being used to identify infected animals at checkpoints.

Ranchers are being urged to report wounds or unexplained animal deaths immediately.

What Farmers Can Do to Protect Their Herds

Every farmer and rancher plays a role in prevention. Here are key steps recommended for 2025:

1. Daily Inspections

Check animals for wounds, especially after branding, calving, or injuries.

Look for foul odors, maggots, or swelling around wounds.

2. Prompt Wound Care

Treat even small cuts with insecticides or wound dressings.

Apply veterinary-approved medications immediately if infestation is suspected.

3. Quarantine New Animals

Isolate livestock imported from risk zones before mixing them with healthy herds.

4. Work With Vets and Authorities

Report unusual infestations right away.

Cooperate with surveillance and inspection programs.

5. Community Awareness

Neighboring farms must work together—screwworms don’t respect property lines.

Shared vigilance can prevent small outbreaks from becoming regional disasters.

Screwworm in Numbers: 2024–2025 Snapshot

$732 million potential annual losses to Texas cattle producers.

$1.8 billion possible broader impact on the Texas economy.

$750 million invested in a sterile-fly production facility in Edinburg, Texas.

300 million sterile flies per week will be released once the facility is fully operational.

165 million in emergency funds deployed by USDA in late 2024.

First U.S. human case in decades reported in 2025, linked to international travel.

Conclusion

The screwworm threat in 2025 is a wake-up call. While it may be a small parasite, its potential damage to the livestock industry, state economies, and national beef supply is enormous.

The good news is that proven methods—like the sterile insect technique, strict surveillance, and rapid veterinary response—are already being deployed. But farmers must remain alert. Daily inspections, proper wound care, and quick reporting are essential.

If vigilance continues, the U.S. can prevent a screwworm comeback and protect both its herds and its economy.