The United States Department of Agriculture (USDA) has confirmed three additional cases of New World screwworm, bringing the total number of confirmed cases to five since the first domestic infestation in nearly 60 years was detected in a Texas calf last week. The development has heightened concerns among ranchers, veterinarians, and agricultural authorities as officials work to prevent the dangerous parasite from establishing a foothold in the country.

New World screwworm is considered one of the most destructive livestock pests in the world. The parasite poses a significant threat to cattle, sheep, goats, horses, wildlife, pets, and, in rare cases, humans. The larvae feed on the living tissue of warm-blooded animals, causing severe wounds, infections, suffering, and potentially death if left untreated. Experts warn that a widespread outbreak could result in substantial economic losses and major disruptions to the livestock industry.

New Cases Raise Concerns Across the Southern United States

According to the USDA’s Animal and Plant Health Inspection Service (APHIS), two new infestations have been confirmed in Texas, including a calf in La Salle County and a goat in Gillespie County. Officials also clarified that a previously reported case involving a dog in Andrews County, Texas, has been reclassified as the first confirmed case in neighboring New Mexico.

The dog involved in the case resides in Lea County, New Mexico, near the Texas border. While the reporting veterinarian was based in Texas, investigators determined that the animal’s primary residence was in New Mexico. This finding has expanded concerns beyond Texas and suggests that surveillance efforts may need to be strengthened throughout the region.

USDA officials emphasized that investigations remain ongoing and that additional information may emerge in the coming days and weeks. Authorities continue to monitor livestock, wildlife populations, and domestic animals for signs of infestation.

Economic and Agricultural Impact Could Be Severe

For more than a year, Texas ranchers have closely monitored the northward movement of the screwworm parasite through Mexico. Agricultural experts have repeatedly warned that the pest’s arrival in the United States was a growing possibility.

Economic projections suggest that a major outbreak could inflict as much as $1.8 billion in damages across Texas alone. Such losses would affect livestock production, veterinary services, animal transportation, trade activities, and wildlife conservation efforts. Ranchers could face increased treatment costs, reduced productivity, and stricter animal movement controls.

Wildlife experts are also concerned about the potential impact on deer, wild hogs, and other native species. Because screwworm larvae infest living tissue, vulnerable wildlife populations could suffer significant losses if the parasite spreads unchecked.

The return of the pest has revived memories of previous outbreaks that caused widespread disruption before eradication efforts successfully eliminated screwworm from the United States decades ago.

Government Response and Industry Reactions

Agriculture Secretary Brooke Rollins announced that the federal government will soon begin awarding grants from a $100 million fund dedicated to developing and deploying technologies aimed at combating screwworm infestations. The funding is expected to support research, surveillance programs, treatment strategies, and other protective measures.

Speaking alongside Texas Governor Greg Abbott during a press conference in Kerrville, Texas, Rollins stressed the importance of a coordinated response. She also confirmed plans to visit Zavala County, where the first recent U.S. case was identified.

Officials have adopted an increasingly aggressive public messaging campaign, with some events featuring “War on Screwworm” materials to highlight the seriousness of the threat.

Despite these efforts, reactions among local ranchers and residents remain mixed. Some producers believe federal actions have been too slow and insufficiently aggressive given the risks posed by the parasite. Others who experienced previous outbreaks have expressed concerns about whether current preparedness levels are adequate to prevent a wider spread.

Questions have also been raised regarding staffing levels within the USDA. Reports last year indicated that numerous veterinarians, laboratory specialists, and support personnel had left the agency following workforce reductions. However, Rollins stated that these departures have not affected the government’s ability to respond to the screwworm situation and insisted that critical operations remain fully functional.

Conclusion

The confirmation of additional New World screwworm cases marks a significant challenge for U.S. agriculture and animal health authorities. With infections now identified in both Texas and New Mexico, officials are intensifying surveillance and response efforts to contain the parasite before it spreads further. While federal agencies have pledged substantial resources and support, many ranchers remain cautious as they prepare for what could become one of the most serious livestock health threats the country has faced in decades. The coming weeks will be critical in determining whether containment efforts can prevent a larger outbreak and protect both the agricultural economy and vulnerable animal populations.

https://www.reuters.com/world/us/usda-confirms-two-additional-cases-new-world-screwworm-united-states-2026-06-08/