PARASITE PANIC

Parasite That Feasts on Living Flesh Spreads to New Animal

A disease once thought defeated has returned, forcing authorities into a race to contain it.

A horse in southern Texas has become the first documented U.S. equine case of the New World screwworm, as officials scramble to contain the spread of the flesh-eating parasite. The pest turned up on the hind limb of a working ranch horse in Presidio County, according to a statement from the U.S. Equestrian Foundation. The screwworm, a fly larva that burrows into and feeds on open wounds, had been eradicated in the United States decades ago before resurfacing in June on a calf near the border. Since then, an infestation has torn through Mexico. “Check horses daily, keep wounds clean and covered as directed by your veterinarian, use veterinarian-recommended fly control products and limit fly access with physical barriers such as fly masks, sheets and clean stabling practices when appropriate,” the foundation said. The Texas Animal Health Commission has restricted animal movement out of infested zones. Of 49 U.S. cases this year, all but one, a dog in New Mexico, have been in Texas. Texas Governor Greg Abbott declared a disaster in June. The Trump administration has since opened a sterile fly dispersal facility to fight the outbreak.