New Mexico animal health officials confirmed two more New World screwworm cases on October 27, 2026, this time in Doña Ana County. One case was a sheep on the New Mexico State University campus in Las Cruces and the other was a cow at a separate location. Earlier in the week the state confirmed a case in a beef cow in Otero County on October 21 and one in a calf in Hidalgo County on October 23.
State and federal teams are adding fly traps and surveillance around each site. Every confirmed case sets up an infested zone of at least 12.4 miles. Animals inside a zone generally need an inspection within five days of moving, proper identification, and treatment where required before they can leave.
The screwworm fly lays its eggs in open wounds, and the larvae feed on living tissue. Officials say cooler weather slows the pest down but does not end the risk. Producers are asked to look for wounds that will not heal or keep getting worse, maggots, foul-smelling discharge, or signs of irritation. Anyone who finds a suspect animal should leave it in place and call the New Mexico Livestock Board.
Why it matters for producers
Screwworm is found by people who look at animals often and act fast. Frequent checks and clear records of where each animal has been keep an infested zone small and keep cattle moving.
