New World Screwworm
New World Screwworms (NWS) are larvae or maggots of the NWS fly (Cochliomyia hominivorax), that cause the painful condition NWS myiasis. New World Screwworm is an invasive pest whose larvae infest the open wounds of warm-blooded animals, including livestock, pets, exotic animals, wildlife, and in rare cases, humans. The risk to humans is incredibly low. NWS larvae feed on living tissue, which can be deadly if untreated.
It is important to note this does not impact food and the food supply is safe
As of June 2026, New World Screwworm has been confirmed in Texas and New Mexico. There is not a confirmed case in Oklahoma. While Oklahoma does not have a confirmed case, Oklahoma producers, pet, exotic and captive wildlife owners, wildlife rehabilitators, veterinarians, hunters and wildlife officials are asked to remain vigilant to help protect Oklahoma’s livestock, pets and wildlife populations.
Proper reporting and identification of NWS is key to slowing the spread of this invasive pest. Producers, pet, exotic and captive wildlife owners, and wildlife rehabilitators who suspect NWS should contact their veterinarian and/or county extension agent immediately to help gather and send proper samples to the laboratory for testing. Do not attempt to self-treat a suspected NWS case before consulting a veterinarian or state official.
You can see all confirmed U.S. cases on the USDA website, here.
Travel restrictions apply to all species including livestock, pets, companion animals and captive wildlife traveling to Oklahoma from an Infested Zone or an Adjacent Surveillance Zone.
As of 6/15/2026:
Traveling from an infested zone
- Any species that originates from an Infested Zone will need to meet the movement requirements for the state of origin AND obtain a permit from the Oklahoma State Veterinarian’s office AND have a CVI that states “all animals listed were individually inspected and found free of wounds.”
Traveling from a surveillance zone
- Any species that originates from an Adjacent Surveillance Zone will need to enter Oklahoma on a CVI issued within 5 days of movement that includes a statement “all animals listed were individually inspected and found free of wounds.
- Frequently inspect all livestock (cattle, sheep, goats, horses, swine, poultry, llamas, alpacas) pets, and captive wildlife for wounds
- This includes navel wounds in newborns, dehorning/castration sites, tick bites, and any other open injuries
- Be aware of the common signs of a NWS infestation including foul-smelling discharge from wounds, cream-colored larvae in wound tissue & unusual wound enlargement
- Report any suspicious wounds or suspected cases of NWS immediately to your veterinarian, County Extension Agent or the ODAFF State Veterinarian at 405-522-6141
Proper reporting and identification of NWS is key to slowing the spread of this invasive pest. Producers, pet, exotic and captive wildlife owners, and wildlife rehabilitators who suspect NWS should contact their veterinarian and/or county extension agent immediately to help gather and send proper samples to the laboratory for testing. Do not attempt to self-treat a suspected NWS case before consulting a veterinarian or state official.
- Monitor game cameras frequently for wildlife with cream-colored larvae in wound tissue & unusual wound enlargement
- If detected, contact a game warden, veterinarian, or ODAFF with location, species, date and time seen. If pictures can be retrieved, please submit to NWS.info@ag.ok.gov.
- When intaking wildlife for rehabilitation:
- Confirm location wildlife originated from
- Examine for common signs for NWS infestation including foul-smelling discharge from wounds, cream-colored larvae in wound tissue & unusual wound enlargement
- Report any suspicious wounds or suspected cases of NWS immediately to your veterinarian, local County Extension Agent, or the ODAFF State Veterinarian at 405-522-6141
Proper reporting and identification of NWS is key to slowing the spread of this invasive pest. Producers, pet, exotic and captive wildlife owners, and wildlife rehabilitators who suspect NWS should contact their veterinarian and/or county extension agent immediately to help gather and send proper samples to the laboratory for testing. Do not attempt to self-treat a suspected NWS case before consulting a veterinarian or state official.
The New World Screwworm can infest the open wounds of warm-blooded animals, including livestock, pets, exotic animals, wildlife, and in rare cases, humans. Travel requirements are in place for pets and companion animals that travel from or near infested zones.
As of 6/15/2026:
Traveling from an infested zone
- Any species that originates from an Infested Zone will need to meet the movement requirements for the state of origin AND obtain a permit from the Oklahoma State Veterinarian’s office AND have a CVI that states “all animals listed were individually inspected and found free of wounds.”
Traveling from a surveillance zone
- Any species that originates from an Adjacent Surveillance Zone will need to enter Oklahoma on a CVI issued within 5 days of movement that includes a statement “all animals listed were individually inspected and found free of wounds.
If you are concerned about NWS in your pet, you are encouraged to contact your veterinarian.
The New World Screwworm can infest the open wounds of warm-blooded animals, including livestock, pets, exotic animals, wildlife, and in rare cases, humans. If you are concerned about NWS or suspect a potential human case, you should contact your primary care physician.
Anyone who suspects NWS should contact their veterinarian, the Oklahoma State Veterinarian’s office and/or their local OSU Extension agent. OSU Extension will have testing materials and can help get proper samples sent to the lab for testing.
Proper reporting and identification of NWS is key to slowing the spread of this invasive pest. Producers, pet, exotic and captive wildlife owners, and wildlife rehabilitators who suspect NWS should contact their veterinarian and/or county extension agent immediately to help gather and send proper samples to the laboratory for testing. Do not attempt to self-treat a suspected NWS case before consulting a veterinarian or state official.
All suspected and confirmed cases of NWS must be reported immediately to the State Veterinarian’s Office at 405-522-6141 upon suspicion of clinical disease.
Reports can be made by anyone, not just veterinarians or laboratories.
Proper reporting will help slow the spread of this invasive pest. Do your part to help Oklahoma agriculture by reporting suspicous and positive cases.
You can learn more about New World Screwworm and the steps the United States Department of Agriculture is taking to help slow the spread of this invasive pest at www.screwworm.gov