Texas quarantines – New World screwworm has been confirmed in Texas for the first time in decades, bringing U.S. totals to 15 confirmed cases as of June 22. The Texas Animal Health Commission has imposed quarantine zones across 14 counties, restricting animal movement to slow spr
For Texas livestock owners, the warning came with a map—and the clock is already running.
As the U.S. confirmed a New World screwworm case in Texas. the first detection in the state in decades. the Texas Animal Health Commission moved fast: quarantine zones covering 14 counties were established to restrict animal movement and prevent the parasite’s spread. By June 22, the nationwide count had reached 15 confirmed cases, with 12 active and 3 inactive.
New World screwworm is a parasitic fly whose larvae feed on the living tissue of warm-blooded animals after eggs are laid in an open wound. The threat has lingered for nearly three weeks since the first reported U.S. case of the parasitic fly.
Over the weekend, the U.S. Department of Agriculture reported three new cases, all in livestock. Two new cattle cases were reported in Edwards County and a new sheep case was reported in Crockett County. With those additions, the number of confirmed U.S. cases climbed to 15 as of 9 a.m. on June 22.
USDA keeps a clear distinction between cases that are still active and those that are no longer spreading. Cases are classified as inactive when the animal has fully recovered or. in cases where treatment was not performed. when appropriate measures have been taken to prevent the spread of New World screwworm. That includes the appropriate disposal of the dead infested animal.
Texas remains the only state in the U.S. continuing to report cases since the parasitic fly re-entered the country after it had been eradicated decades earlier.
The biology matters, because it explains why officials are focused so heavily on movement. Infestations start when a female screwworm fly lays eggs on a wound or body opening. The eggs hatch into larvae that burrow into the wound and feed on living tissue. After about seven days of feeding, the larvae drop to the ground, burrow into the soil, and pupate. The adult screwworm fly emerges from the soil after seven to 54 days.
USDA says the current risk to animals and people in the United States remains very low. The agency also says New World screwworm is not contagious. Instead, spread depends on eggs being laid on wounds or body openings, which is why quarantines and handling rules are central to the response.
The timeline of cases in Texas shows how the situation has expanded within the state. As of the date cases were confirmed, Texas had 14 cases:
June 21: Two active domestic cattle cases in Edwards County.
June 20: One active domestic sheep case in Crockett County.
June 12: One inactive domestic sheep case in Sutton County.
June 11: Two active domestic goat and cattle cases in Edwards County; one active domestic cattle case in Tom Green County; and one inactive domestic cattle case in Zavala County.
June 9: One active domestic cattle case in Edwards County.
June 8: One active domestic goat case in Gillespie County; and one active domestic cattle case in La Salle County.
June 7: One active domestic cattle case in La Salle County.
June 5: One active domestic cattle case in Zavala County.
June 3: One active domestic cattle case in Zavala County.
New Mexico has also recorded a case. A case was confirmed in a dog in New Mexico. It was first reported on June 7 by a veterinarian in Andrews County, Texas, but the U.S. Department of Agriculture classifies it as a case in Lea County, New Mexico because the dog lives there. That New Mexico case has now been classified as inactive.
While the federal count is built on confirmed cases, the day-to-day impact on farms and ranches is shaped by where Texas says animals can and cannot move.
The Texas Animal Health Commission grouped 14 counties across West, South and Central Texas because some are under quarantine. The goal is to restrict animal movement and keep animals out of the areas where recently reported cases have appeared. The quarantine is set to remain in effect until the commission lifts it.
The quarantine zones are scheduled to take effect in phases:
Zone 1 (effective June 3): Uvalde and Zavala counties.
Zone 2 (effective June 7): La Salle and Webb counties.
Zone 3 (effective June 9): Gillespie, Kerr and Kimble counties.
Zone 4 (effective June 10): Edwards, Sutton and Val Verde counties.
Zone 5 (effective June 12): Tom Green and Coke counties.
Zone 6 (effective June 13): Kimble, Schleicher and Sutton counties.
Zone 7 (effective June 20): Crockett, Schleicher and Sutton counties.
The underlying worry for producers is not just the number of cases. but the pattern of exposure that comes with a fly that returns to the soil and emerges again. Larvae drop to the ground after feeding. then pupate before the adult fly emerges from seven to 54 days later—meaning timing and containment matter.
USDA describes New World screwworm as a parasitic fly that impacts livestock, pets, wildlife, and less commonly people and birds. In practice, the fear tends to land where wounds are most likely—among warm-blooded animals whose injuries can become entry points.
Texas now sits at the center of that response. The quarantines covering 14 counties reflect the state’s role as the only one still reporting new cases since the fly’s return. and the weekend’s additions kept the pressure on: two more active cattle cases in Edwards County and one more active sheep case in Crockett County pushed the U.S. total to 15 as of 9 a.m. on June 22.
For ranchers and livestock operators watching the USDA dashboard and the Texas quarantine zones, the message is straightforward: until the commission lifts restrictions, the movement decisions made every day can determine whether the next confirmed case remains an exception or becomes the rule.
New World screwworm Texas quarantine USDA livestock Edwards County Crockett County animal health parasite fly Gillespie County Sutton County Lea County
So wait, screwworm is back like it’s a normal thing now? Great.
14 counties?? That map is gonna ruin a bunch of farmers’ lives. Can’t they just spray or something instead of quarantining animals for weeks?
I don’t get it, aren’t screwworms mostly like… from dirty wounds and stuff? If people cleaned them better maybe this wouldn’t spread. Quarantine seems like a band-aid.
New World screwworm sounds made up tbh, like why is it “New” if it’s in Texas again. So the larvae eat living tissue, that’s terrifying, but only 15 cases? I feel like they’re overreacting and under-explaining how it actually got there in the first place.