LDAF encourages vigilance regarding New World Screwworm movement

News

Press release

For immediate release: May 14, 2025

The Louisiana Department of Agriculture and Forestry’s (LDAF) Commissioner Mike Strain, DVM, applauds the U.S. Department of Agriculture’s (USDA) decision to close the United States’ southern border to shipments of cattle, bison, and horses, due to the continued and rapid northward movement of New World Screwworm (NWS, Cochliomyia hominivorax) in Mexico.

This pest is an extreme threat to the health of U.S. livestock, companion animals, and wildlife. NWS can infest livestock, pets, wildlife, occasionally birds, and in rare cases, people. NWS is not currently in Louisiana , but because of the known proximity of the pest in Mexico, and Louisiana’s proximity to major travel and trade routes, vigilance is essential.

“The decision to close the southern border to livestock imports is the right one," said LDAF Commissioner Mike Strain. “We must protect the livestock industry in the United States.”

LDAF encourages animal owners to be vigilant for New World Screwworm by:

• Checking animals regularly, especially if you or they have traveled internationally.

• Owners should inspect animals for wounds and treat them promptly.

• If owners/producers move pets and livestock across borders, ensure the animals are properly inspected and obtain appropriate movement permits/documents.

• Be alert when returning from affected regions (Central/South America, Mexico).

Symptoms to look for include unusual behavior or head shaking; evidence of fly strike; bad odor (smell of decay); wounds that worsen over time; and visible maggots in or around wounds.

If animals exhibit signs of NWS, owners should consult their local veterinary professional and notify state or federal animal health officials. Owners can call LDAF’s Office of Animal Health at 225-925-3980 to report potential cases.