New World Screwworm Update from the American Horse Council

As of June 8, 2026, there have now been multiple New World Screwworm detections in Texas, with one being in a county bordering New Mexico. Livestock movement restrictions are in place in Texas and information can be found here: https://www.tahc.texas.gov/

The American Horse Council (AHC) is working to share critical information for horse owners regarding the current New World Screwworm (NWS) infestation recently announced in Texas.

The Facts About Screwworm from the American Horse Council

On June 3, 2026, the U.S. Department of Agriculture confirmed New World Screwworm in the umbilical area of a calf in Zavala County, Texas. This expansion into the United States is alarming and AHC wants to make sure you know about the potential risks of this parasitic fly to horses.

While this might seem like an overwhelming and scary situation, we’ve dealt with this before and have confidence in current science based strategies. The United States historically was afflicted with Screwworm for hundreds of years before successfully eliminating it from the country in the 1960s using many of the same methods we use now.

We’ve eliminated it before, and have full faith we’ll do it again, but only if all horse owners do their part to stay vigilant and follow state guidelines for animal movement.

Currently, the US-Mexico border is closed to all livestock exports from the US to Mexico for any reason. This includes all horses. All livestock imports from Mexico to the US are still closed as well. Further, Canada is now restricting all imports of any livestock, including horses, from Texas, and prevents any livestock from entering Canada that have resided in or transited Texas in the previous 21 days prior to importation to Canada.

For updates, make sure to check our website: https://horsecouncil.org/screwworm/