Tennessee Officials Are Warning Livestock And Pet Owners About The Threat Of New World Screwworm—A Dangerous Parasitic Fly Whose Larvae Feed On Living Tissue. State Veterinarian Dr. Samantha Beaty Says Recent Cases In Mexico Have Raised Concerns About Reintroduction In The U.S., Including Tennessee. Owners Should Watch For Wounds That Won’t Heal, Foul Odors, Or Visible Larvae. If Suspected, Report It Immediately To The State Veterinarian’s Office Or The USDA.