06/04/2026
đ¨First New World Screwworm case in Texas confirmedđ¨
Today a calf in Zavala County tested positive for New World Screwworm (NWS). This is the only confirmed case in Texas so far, but we will likely be seeing more cases pop up in the near future as we head into peak fly season.
âWhat can animal owners do to prepareâ
1ď¸âŁFly control! Start early and stay consistent. Keep animal areas clean and free of manure, use feed-through and topical products, and check out fly predators from distributors like Spalding Labs or Arbico Organics.
2ď¸âŁMonitor your herds! Keep a close eye out for wounds or animals with higher fly/tick burden. Stay proactive in treating wounds and external parasites to lessen your risk.
3ď¸âŁPrepare handling equipment/facilities and isolation spaces! Having a plan in place for how you can handle, move, or isolate any species on your property is vital to having smooth and efficient responses to both routine and non-routine situations.
4ď¸âŁIf you suspect NWS in one of your animals, call your vet immediately! Additionally, any suspected cases in live or deceased animals (including domestic, exotic, & wildlife species) should be reported to the USDA - you can find more info on how to report cases here: https://www.aphis.usda.gov/animals/animal-health/livestock-and-poultry-disease/stop-screwworm
Once you report the case youâll be provided with further instruction, but the animal will likely need to be moved to isolation where sample collection, treatment, and monitoring can take place.
Want to learn more about NWS? Check out Texas A&M AgriLifeâs resources on their page dedicated to New World Screwworm (https://agrilifeextension.tamu.edu/new-world-screwworm)
In response to the increased activity in Mexico regarding New World screwworm, Texas A&M AgriLife provides research-backed information to Texas citizens.