The United States now has its first confirmed case of New World screwworm in wildlife. USDA says the parasite turned up in an elk on a game ranch in Pecos County, Texas, reported after a hunter harvested it. New Mexico confirmed a case in a beef cow in Otero County the same week.
Dog owners should care because screwworm larvae do not wait for a carcass. They burrow into living flesh, and a dog’s cut or hot spot is as good as a cow’s hide. USDA lists pets alongside livestock, wildlife, and, in rare cases, people. The parasite was wiped out here in 1966 and stamped out of the Florida Keys in 2017, but it has been moving north through Mexico and Central America. Wildlife is harder to contain than a herd.
Signs: maggots in a wound or body opening, a wound that keeps getting bigger or draining, a smell of decay, and a dog who keeps shaking their head or fussing at something you cannot see. Any of those means a vet visit that day.
What this means for your dog: if you live in or drive through the affected part of Texas, make wound checks a daily habit, especially after hikes, fence lines, and rough play. An untreated scratch is an open door. Keep tick control current, since ticks leave exactly the kind of small wound a screwworm fly is hunting for, and if you have been inside an infested zone, check your truck or trailer for flies before you pull out. The USDA announcement lists the signs in detail, and the Texas Animal Health Commission lets you search your address against the infested zone map. In that zone, ask your vet about preventive nitenpyram, which the FDA cleared for screwworm in dogs in September.