The return of New World screwworm Texas cases has triggered an emergency response from federal regulators, after the flesh-eating parasite reappeared in the United States for the first time in decades and prompted the FDA to fast-track a treatment for infected pets.

An Emergency Approval

The Food and Drug Administration issued an emergency approval allowing an over-the-counter drug to be used to treat dogs and cats for New World screwworm, a parasite largely wiped out from U.S. livestock back in the 1960s. Its resurgence follows DOGE-led government cuts that gutted ongoing efforts to keep the pest from spreading.

On Thursday, the FDA approved generic Nitenpyram tablets, an oral medication typically used to kill fleas, for treating infected dogs, puppies, cats, and kittens.

How the Outbreak Began

New World screwworm is a parasitic fly whose larvae burrow into the healthy tissue of cattle, deer, horses, and other warm-blooded animals. The first case was discovered in May in a three-week-old calf in La Pryor, Texas, near the Mexico border. Since then, the count has climbed to seven cases, affecting cattle, goats, and a dog across Texas and New Mexico, according to the Department of Agriculture.

The parasite’s life cycle is gruesome. A female fly lays her eggs in open wounds or body openings, with wounds as small as a tick bite enough to attract her. The eggs hatch into maggots that feed on living flesh for about seven days before dropping to the ground, burrowing into the soil, and emerging as adult flies to begin the cycle again. While infestations usually strike animals, they can occasionally affect people. The most recent human case in the U.S. was reported last year in Maryland, in a traveler returning from El Salvador who later recovered.

A Threat to an Already Strained Beef Industry

Experts warn that a wider outbreak could deal a serious blow to a cattle industry already under pressure. More infections could mean more calf deaths, weight loss in adult cattle, and fewer animals suitable for sale, all of which would reduce the amount of beef reaching the market.

The timing is especially difficult. The U.S. cattle herd has fallen to its lowest level in 75 years, dropping to 86.2 million head as of January 1, the fewest since 1951. Even containment efforts could squeeze supply further, as the government may impose cattle movement restrictions, limit border crossings, or quarantine certain herds.

Consumers may feel the impact at the grocery store. Beef prices have already surged roughly 75 percent since December 2020, with average ground beef rising from $3.95 to $6.89 by April. The USDA expects beef production to dip in 2027 and projects cattle prices to hit new highs as supplies stay tight.

Blame Over the Funding Cuts

The screwworm’s return has reignited criticism of recent government cuts. Last year, the Elon Musk-led Department of Government Efficiency, launched under the Trump administration, slashed funding for a project dedicated to monitoring and containing screwworm in Central America.

The timing drew particular concern. The funding was eliminated just days before the U.S. lifted a temporary suspension of cattle imports from Mexico, allowing livestock to cross the border without the monitoring previously paid for by USAID.

Agriculture officials and cattle industry leaders had sounded the alarm at the time and spent months urging the government to act as infections moved north through Mexico. Texas Agriculture Commissioner Sid Miller told NBC News those pleas were ignored. He criticized the USDA for moving too slowly and relying on a partial solution that would take years to implement, urging President Trump to throw every available federal resource at the threat before it becomes a full-blown agricultural disaster.

Lessons From the Past

History offers a sense of the stakes. The U.S. eradicated screwworm in the 1960s through a massive sterile fly program that cost about $42 million at the time, equivalent to roughly $452 million today.

Even after that success, isolated outbreaks occurred, including one in Texas in 1976 that cost ranchers an estimated $452 per head of cattle in today’s dollars, totaling $732 million. Those losses stemmed from cattle deaths, weight loss, hide damage, and the cost of surveillance and treatment. Past outbreaks did push beef prices higher, though not always in dramatic nationwide spikes, partly because the industry was far stronger in the 1950s and 60s, with much larger herds. The USDA estimates another outbreak on the scale of the 1976 event could cause as much as $1.8 billion in economic damage.

What to Watch For

Containment is now the central focus, and authorities on multiple fronts are moving to limit the spread:

• The Canadian Food Inspection Agency has barred livestock that originated in or passed through Texas within the prior 21 days from crossing the border.
• Florida has enacted emergency rules restricting imports of warm-blooded animals from infested zones.
• The USDA is spending $750 million on a new Texas facility capable of producing about 300 million sterile screwworms per week, though it will not be operational until at least 2027.

On the ground near the infected calf, officials are implementing cattle quarantines, movement controls, and surveillance within roughly a 12-mile radius, trapping flies along the border, and releasing millions of sterile male flies in the region. The USDA says 75 personnel are actively responding in Texas, backed by hundreds more providing laboratory, logistics, and air support nationwide.

The Road Ahead

For now, the fight against screwworm is a race against time. With a key containment facility still years from completion and the cattle herd already at historic lows, officials face mounting pressure to stop the parasite before it spreads further. The emergency pet treatment offers one tool, but the broader battle to protect the nation’s livestock, and keep beef prices in check, is only beginning.