New World Screwworm
New World Screwworm: What Livestock Producers Need to Know Right Now
Resources and action steps from the Fort Valley State University fly control webinar series
A recent webinar hosted by Fort Valley State University covered an important and developing situation for livestock producers: the return of New World Screwworm (NWS) in parts of the United States. The full webinar recording is now available:
📹 Watch the Fly Control/New World Screwworm Webinar on YouTube(YouTube automatic captions/subtitles will be available within 24–48 hours of posting.)
Where Is New World Screwworm Right Now?
New World Screwworm is not currently in the Southeast. However, confirmed cases are active in Texas and New Mexico, and the situation continues to develop.
Texas: Confirmed in 3 locations, with the most recent case appearing north of the previous areas. Cases involve goats and cattle.
New Mexico: One confirmed case in a dog, still limited to a single area.
We hope eradication efforts are successful and that spread remains contained to these regions. Producers in Texas and neighboring states should remain especially vigilant.
📍 View the current confirmed case map — USDA APHIS
The USDA-APHIS has a dedicated resource hub at Screwworm.gov with up-to-date information for all producers.
What Is New World Screwworm?
New World Screwworm is a parasitic fly (Cochliomyia hominivorax) whose larvae (maggots) burrow into the living tissue of warm-blooded animals. Unlike common blow flies that feed on dead tissue, screwworm larvae feed on living flesh, causing serious wounds that grow larger and smell strongly. Animals in affected areas can deteriorate rapidly without early detection and treatment.
The primary defense is vigilance: check your animals thoroughly and often.
If You Are Near an Affected Area
Check every animal regularly — all over their body — for maggots.
Prevention
Control flies and ticks on your property and animals
Reduce the chances of animals being wounded
Delay animal processing if possible until fly season has passed or fly populations are reduced
If You Suspect Screwworm — Act Immediately
Call your veterinarian and your state or USDA authority right away if you observe:
Maggots on or in a live animal
A wound that keeps growing larger
A wound with a strong, foul odor
An animal that appears to be in significant pain
📞 State Department of Agriculture directory 📞 USDA Area Veterinarian in Charge
Immediate Steps While You Wait
Isolate the animal if possible — do not move it off your property
Remove maggots from the wound using hydrogen peroxide or another appropriate method
Kill all maggots removed from the animal — save some by placing them in 70% isopropyl (rubbing) alcohol for professional identification by your state veterinarian or veterinarian
Treat the wound with a screwworm pesticide wound spray such as Catron, Prozap, or Durvet
Administer ivermectin injectable with veterinarian approval
Treat with antibiotics as directed by your veterinarian
Continue to monitor the animal closely
If You Travel Through an Affected Area
Before leaving any area where screwworm may be present:
Thoroughly check all animals with you for fly eggs in wounds — eggs can be as small as a tick bite. Check eyes, ears, nose, mouth, genital/anal areas, feet, and any existing wounds.
Make sure no flies are present in your vehicle or trailer before departing.
Wild, Feral, or Stray Animals
If you suspect a wild, feral, or stray animal may have screwworm, do not handle the animal. Contact:
Your local DNR / Department of Natural Resources
Your State Department of Agriculture
Animal Control as needed
Georgia-Specific Contacts
Situation Contact Domestic animals Your veterinarian — first call Georgia domestic animals (state) Office of the State Veterinarian — 404-656-3667 / AnimalHealth@agr.georgia.gov Georgia wildlife Georgia DNR — 1-800-366-2661 General USDA questions screwworm@usda.gov
Outside Georgia: Contact your State Veterinarian, State Animal Health Official, or local USDA APHIS office.
Resources at a Glance
Information compiled from multiple sources by Dr. Niki Whitley, Fort Valley State University Extension. For questions, contact whitleyn@fvsu.edu.
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