06/17/2026
⚠️ VETERINARY ALERT: NEW WORLD SCREWWORM UPDATE ⚠️
Arizona pet owners, livestock producers, and animal caretakers should be aware of the ongoing New World Screwworm (NWS) outbreak affecting Mexico and the recent confirmed cases in Texas and New Mexico. While no cases have been reported in Arizona, awareness and early detection are critical.
🪰 What is New World Screwworm?
New World Screwworm is a parasitic fly whose larvae (maggots) feed on the living tissue of warm-blooded animals. Unlike typical maggots that consume dead tissue, screwworm larvae invade healthy tissue, causing severe wounds, infections, suffering, and potentially death if left untreated.
🐾 Animals at Risk:
• Cattle, horses, sheep, goats, and other livestock
• Dogs and cats
• Wildlife
• Rarely, humans can also be affected
🔍 Signs to Watch For:
• Non-healing or rapidly worsening wounds
• Foul-smelling lesions
• Visible maggots in wounds
• Excessive licking or irritation
• Depression, lethargy, or decreased appetite
Recent U.S. cases have been confirmed in cattle, a goat, and a dog in Texas and New Mexico, prompting increased surveillance and response efforts.
✅ Prevention Tips:
• Check pets and livestock regularly for wounds.
• Promptly clean and treat any cuts, surgical sites, or injuries.
• Keep pets on veterinarian-recommended parasite prevention year-round.
• For dogs, products such as NexGard® and NexGard PLUS® contain afoxolaner, which has been shown to kill New World Screwworm larvae and may provide an additional layer of protection for dogs in areas of concern or for those traveling to affected regions.
• Seek veterinary care immediately for wounds that worsen, have an odor, or contain larvae.
• Report suspicious cases to your veterinarian or state animal health officials.
✈️ Traveling to Mexico with Your Pet?
If you plan to travel to Mexico with your dog, cat, horse, or other animals, take extra precautions due to the ongoing New World Screwworm outbreak.
Before returning to the United States:
• Thoroughly inspect your animal for any wounds, cuts, or skin lesions.
• Avoid allowing pets to roam unsupervised, especially in rural or livestock areas.
• Keep your dog current on veterinarian-recommended preventatives, including products such as NexGard® or NexGard PLUS® when appropriate.
• Seek veterinary attention immediately for any wound that is not healing normally.
• Be aware that animals returning from affected areas may be subject to additional inspection requirements at U.S. ports of entry.
Arizona remains free of New World Screwworm, but our proximity to affected regions and frequent travel between Arizona and Mexico make vigilance important. Early detection and prompt treatment are essential to protecting our pets, livestock, and wildlife.
Learn about New World Screwworm life cycle, eradication methods, surveillance, and how you can help control its spread.