As reports of New World screwworm continue to make headlines, many pet owners are wondering whether they should be concerned. While this parasite was previously considered eradicated, in 2026 it has been confirmed in both New Mexico and Texas, making awareness important—especially for pet owners who travel with their animals or live near international borders.
Understanding what New World screwworm is, how it spreads, and how to protect your pets can help keep them healthy.
What Is New World Screwworm?
New World screwworm is the larval stage of the New World screwworm fly (Cochliomyia hominivorax). Unlike common fly maggots that feed on dead tissue, screwworm larvae feed on healthy, living tissue. This makes infestations extremely painful and potentially life-threatening if left untreated.
The parasite can affect:
- Dogs
- Cats
- Horses
- Livestock
- Wildlife
- Birds
- Occasionally, people
How Do Pets Become Infected?
Adult female screwworm flies are attracted to open wounds, even very small ones.
They lay eggs around the edges of the wound, and the eggs hatch within about a day.
The larvae burrow into healthy tissue and feed as they grow, causing the wound to become larger and more severe.
Common sites of infestation include:
- Cuts or scrapes
- Surgical incisions
- Bite wounds
- Tick bite sites
- Ear wounds
- Umbilical cords of newborn animals
Signs of a Screwworm Infestation
Early recognition is important. Contact your veterinarian promptly if you notice:
- A wound that suddenly becomes larger or more painful
- Bloody or foul-smelling discharge
- Visible movement or larvae within a wound
- Excessive licking or chewing at one area
- Swelling around a wound
- Lethargy or decreased appetite
- Fever or signs of illness
Because the larvae continue feeding on living tissue, the damage can progress rapidly.
Is New World Screwworm Found in the United States?
Yes. In 2026, New World screwworm was confirmed in both Texas and New Mexico, marking the first U.S. detections in years. These cases have prompted an aggressive response from the U.S. Department of Agriculture (USDA), including quarantines, enhanced surveillance, animal movement restrictions in affected areas, and the release of sterile male flies to help stop the parasite from becoming reestablished.
While the overall risk to most household pets remains low, pet owners—particularly those in the Southwest or those traveling with animals—should stay informed and promptly seek veterinary care for any wound that is not healing normally.
Early detection is critical because screwworm larvae can cause extensive tissue damage in a short period of time.
How Can Pet Owners Protect Their Pets?
Keep Wounds Clean
Promptly clean and monitor any cuts, scrapes, or skin injuries. Even small wounds should be checked daily for signs of infection or delayed healing.
Follow Post-Surgical Instructions
If your pet has recently had surgery, follow your veterinarian’s recommendations for incision care and prevent your pet from licking or chewing the area.
Use Fly Control Measures
Reducing exposure to flies can help decrease the risk of many wound-related complications. Keep outdoor areas clean and dispose of waste promptly.
Seek Veterinary Care Early
If a wound appears to worsen instead of heal, or if you notice discharge, swelling, or larvae, have your pet examined immediately.
Follow Travel Requirements
If you travel internationally with your pet, especially to areas where New World screwworm is present, be aware of current import and health requirements before returning home.
Why Early Veterinary Care Matters
A screwworm infestation is a medical emergency. Treatment involves removing the larvae, thoroughly cleaning the wound, managing pain, and treating any
secondary infections. Some pets may require sedation or anesthesia, wound management, antibiotics, and ongoing follow-up care.
The earlier treatment begins, the better the outcome.
Staying Vigilant
News about animal diseases can understandably be concerning, but it’s important to remember that New World screwworm is not a common threat for most pets in the United States. Animal health officials actively monitor for this parasite, and veterinary professionals are trained to recognize unusual cases.
The best protection is routine preventive care, prompt attention to wounds, and regular veterinary visits.
We’re Here to Help
If your pet has a wound that isn’t healing, has recently traveled internationally, or you’re concerned about any unusual skin lesion or fly-related injury,
don’t wait to seek veterinary care.
Our veterinary team is committed to keeping you informed about emerging animal health concerns and providing prompt, compassionate care whenever your pet needs it. If you have questions about New World screwworm or your pet’s health, please contact our hospital.