A group of Texas Representatives is urging U.S. Department of Health and Human Services Secretary Robert F. Kennedy Jr. to immediately roll out new treatments to combat the New World Screwworm (NWS) infestations in sheep and goats.
Last week, Rep. Roger Williams (R-TX) led the group in issuing a letter to Secretary Kennedy asking he expedite the development and distribution of additional injectable, preventative and reactive treatments for NWS.
The letter also comes just after Congress passed the 2026 Farm Bill, which helps fund federal agriculture and animal health programs that protect livestock from threats like NWS.
While NWS is most present in parts of South America, it recently returned to the United States through Central America and Mexico. It can cause severe and often deadly damage to both animals and people.
“The threat of a New World Screwworm outbreak north of the American Mexican border poses serious risks to our livestock industry and food supply,” Rep. Williams said.
In the letter, the group said the current Food and Drug Administration-approved treatments primarily focus on cattle, leaving other animals at risk.
“The American Southwest is also home to millions of sheep and goats, that, without the proper treatment, could become nesting sites for millions of flies, increasing the likelihood of infestation,” the group wrote.
Expanding access to other proven treatments like doramectin and ivermectin for all farm and ranch animals is crucial, the group argues.
“This will be vital to maintain the enormous farming and ranching industry in the United States Southwest in the event of further northern spread of screwworm,” the group wrote.
The letter’s Texas supporters include Reps. Chip Roy (R), Brian Babin (R), Pete Sessions (R), August Pfluger (R), Michael Cloud (R), Jake Ellzey (R), Michael McCaul (R) and John Carter (R).

