A New Mexico dog, the first companion animal confirmed with New World screwworm in the US since the parasite's return, has reportedly recovered from the infestation. The case, initially misidentified in Andrews County, Texas, was reclassified as being in Lea County, New Mexico, bordering Texas, after officials clarified the dog's residence. This dog case is deemed isolated by the USDA, though its travel and exposure history prior to infestation remain unknown, prompting an investigation into potential local screwworm populations.
The recovery of the dog comes amidst a growing number of New World screwworm detections in the US, with a total of 12 cases reported as of June 12, 2026, including several in Texas. The first case was identified on June 3, 2026, in a 3-week-old calf in Zavala County, Texas, and cases have since spread to La Salle and Gillespie Counties in Texas, as well as Lea County in New Mexico. The USDA and local partners are implementing containment measures such as quarantines and deploying 4 million sterile flies per week near detection zones.
The re-emergence of the screwworm, which was declared eradicated from the US in 1966, presents a significant challenge, especially with US cattle herds at a 75-year low. Officials are concerned about the spread, with one expert noting that the method used to eradicate the screwworm previously might be insufficient against the current, potentially harder-to-contain enemy. The USDA has invested in a $21 million breeding facility in Mexico for sterile flies and broken ground on a $750 million production factory at Moore Air Base in Edinburg, Texas, aiming to produce 100 million sterile flies per week by late 2027 and ultimately 300 million a week, though this timeline might be challenged by the parasite's rapid reproduction in warm weather. Climate change, marked by warmer winters, is also cited as contributing to the parasite's expanding habitat.
