USDA Confirms Two Additional Cases of New World Screwworm in the United States

On June 8, 2026, the U.S. Department of Agriculture's (USDA) Animal and Plant Health Inspection Service (APHIS) reported two new cases of New World screwworm (NWS) affecting a calf in La Salle County and a dog in Andrews County, both in Texas. This alarming news highlights the ongoing threat that NWS poses to pets and livestock.

Key Takeaways for Pet Owners

• Understanding NWS: NWS is a pest that infests living tissue, leading to severe wounds and suffering in animals. It can affect pets, livestock, and even wildlife.
• Recent Cases: The dog in Andrews County had recently traveled to Mexico, suggesting a possible route for the infestation. This emphasizes the importance of being vigilant for signs of NWS, especially for pets that travel.
• Symptoms to Watch For:
  • Draining or enlarging wounds
  • Maggots or egg masses
  • Signs of discomfort in animals
  • Lesions in body openings such as the nose, ears, and genitalia
• Immediate Action: If pet owners notice any of these symptoms, they should contact their veterinarian or local animal health officials immediately.
• Current Response Efforts: USDA and the Texas Animal Health Commission (TAHC) have activated a response team of 75 people on the ground, with additional support for diagnostic and logistical operations.
• Surveillance Measures: The USDA has established a 20 km infested zone with strict quarantines and heightened surveillance to manage the spread of NWS.
• Sterile Fly Releases: The USDA is releasing sterile NWS flies in affected areas to control the population and prevent further infestations.
• Food Safety: The USDA assures that the U.S. food supply remains safe, as NWS does not infest food products.

What Can Pet Owners Do?

Pet owners are encouraged to:

• Conduct regular checks on their pets for any signs of screwworm infestation.
• Report any suspicious lesions or symptoms to their veterinarian or contact the USDA.
• Stay informed about the ongoing situation and follow guidelines set by the USDA and TAHC.

For more detailed information and ongoing updates, please refer to the full article from the USDA available here.