New Mexico Expands Surveillance Following Second NWS Case
September 18, 2026
New Mexico animal health officials have confirmed the state’s second case of New World screwworm, identified Sept. 17 in a horse in Grant County.
In response, state and federal officials are expanding surveillance and fly-trapping around the affected location to identify any additional cases and determine whether the pest has spread beyond the affected animal.
“We are working as quickly as possible to increase surveillance, inspect animals and monitor for additional cases in and around the affected area,” said State Veterinarian Dr. Samantha Holeck with the New Mexico Livestock Board.
A minimum 12.4-mile radius infested zone is being established around the affected animal’s location. Within the infested zone, animals must be inspected and, if necessary, treated before moving within or out of the area. These measures are intended to support early detection, treatment and safe animal movement while officials conduct additional surveillance.
A broader surveillance zone will extend beyond the infested zone to support ongoing monitoring and early detection. Within the surveillance zone, state and federal officials will conduct increased animal health surveillance and fly-trapping to detect New World screwworm (NWS) and determine whether additional cases are present.
Routine animal movement, including travel to livestock auctions, fairs, veterinary appointments or for recreational purposes, is generally not restricted unless an inspector identifies a higher-risk situation based on an animal’s health or wound status that could increase the risk of spread. In those cases, movement may be delayed or adjusted in coordination with New Mexico Livestock Board personnel.
In coordination with the New Mexico Livestock Board, the New Mexico Department of Wildlife is addressing wildlife surveillance, and monitoring hunting activities and the movement of dogs and horses through or near the affected areas. Hunters, recreational users and animal owners should remain vigilant and monitor horses, dogs and other animals for wounds or other signs consistent with NWS.
“We appreciate the continued vigilance and cooperation of livestock producers, veterinarians, pet owners and other stakeholders as we respond to this second confirmed case of New World screwworm in New Mexico,” said New Mexico Secretary of Agriculture Jeff Witte. “Our immediate focus is expanding surveillance around the affected area so we can identify any additional cases as quickly as possible. Early detection and prompt reporting are critical to limiting the spread of this pest, and we encourage everyone to remain vigilant and work closely with animal health officials.”
State and federal officials continue to work closely with veterinarians, livestock producers and local partners to conduct surveillance, investigate suspect cases, expand fly-trapping and implement response measures as needed.
Signs of New World screwworm may include:
- Wounds that fail to heal or worsen over time
- Presence of maggots in a wound
- Foul-smelling or draining wounds
- Animals persistently licking, biting or aggravating a wound
- Irritation, discomfort or unusual behavior around an injury site
These signs may be noticed before an infestation is recognized and can be mistaken for illness, injury complications or other health conditions. Animal owners should closely inspect wounds that are not healing normally.
Anyone who observes a suspicious wound or suspects NWS should immediately contact the New Mexico Livestock Board and avoid moving the affected animal.
In addition to frequently monitoring animals, producers should keep open wounds clean and covered. Animals infested with NWS should be treated immediately under the direction of a veterinarian.
Additional information, maps of affected areas, reporting resources and updates are available at ScrewwormNM.org.
Source: New Mexico Department of Agriculture
