Rep. Don McLaughlin warned that the New World screwworm poses a growing threat along the U.S.-Mexico border and urged federal action, saying the parasite could affect livestock, wildlife, humans and pets.
In a video addressed to President Donald Trump, McLaughlin said the risk was increasing and that existing channels were moving too slowly. “We are facing a tremendous threat along our southern border in the New World screw worm,” he said. “If the screw worm hits here, it’s not just a livestock issue, it will hit wildlife, it will hit humans, it will hit pets, it will be devastating to our country and to our nation.”
McLaughlin said he was urging Trump to declare a national emergency to accelerate the response and involve multiple federal agencies, including the U.S. Department of Agriculture and the Department of Homeland Security. He said the Texas governor recently declared a state emergency and brought state agencies together to address the threat.
This isn’t something we can afford to ignore or slow-roll in Washington. The New World Screwworm poses a serious and growing threat to South Texas — not just to cattle, but to wildlife, human health, and the very economy of our region.
— Rep. Don McLaughlin (@donfortexas) February 6, 2026
I’ve said it before and I’ll say it again:… pic.twitter.com/d183JTnoad
The lawmaker said the United States previously eradicated the New World screwworm in the 1960s and 1970s using a sterile fly release program that deployed between 500 million and 600 million flies per week. He said current global production capacity is far lower and that the United States no longer produces sterile flies domestically, relying instead on foreign facilities.
The Centers for Disease Control and Prevention describes the New World screwworm as a fly whose larvae infest open wounds and consume the living tissue of warm-blooded animals, including livestock and humans, according to the agency’s screwworm explainer. The CDC says infestations primarily affect cattle, sheep and horses but can also occur in people, domestic dogs and wildlife.
The CDC says the parasite was eliminated from the United States through intensive eradication efforts but remains endemic in parts of South America, Central America and the Caribbean. Since 2023, a growing outbreak has been reported in Central America and Mexico, where the parasite had previously been eradicated, the agency said.
Federal regulators have taken recent steps to address the risk. On Feb. 5, the U.S. Food and Drug Administration issued an Emergency Use Authorization for an injectable ivermectin product to prevent New World screwworm infestations in cattle, according to an FDA statement.
The FDA said the authorization allows over-the-counter use of the drug under specified conditions and concluded that available scientific evidence suggests the product may be effective when administered at certain points, such as when wounds appear or during routine livestock procedures. The agency said the authorization will remain in effect until it is revoked or a related public health emergency declaration is terminated.
McLaughlin said producers in South Texas were increasingly concerned and that delays could allow the parasite to spread beyond the region. In his message, he said the issue could affect not only southern states but the entire country if it is not addressed quickly.
“This is something that will affect not just the southern states, it will affect the whole United States,” McLaughlin said in the video, urging federal officials to move faster and coordinate a broader response.
