Texas reports first equine infection of New World screwworm on ranch horse

A horse in southern Texas has been infected with the New World screwworm, marking the first US equine infection as health authorities race to contain an outbreak of the flesh-eating parasite.

The pest was discovered on the hind limb of a working ranch horse in Presidio county, according to a statement on Thursday from US Equestrian Foundation.

The foundation advised horse owners to monitor the animals daily for wounds, foul odor or maggots.

The screwworm, a fly larva, can nestle into and infest open wounds.

“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’s statement read.

The Texas Animal Health Commission, has restricted the movement of warm-blooded animals outside of infested zones in parts of Presidio and Jeff Davis counties, among several others, to curb new infestations.

After being eradicated decades ago, the screwworm was detected in June on a calf in Zavala county, near the US-Mexico border. A screwworm infestation has spread throughout Mexico.

Of the 49 US cases recorded this year, all have been in Texas, except for one in New Mexico, where the pest was found on a dog, according to the US Department of Agriculture.

The resurgence of the parasite, which can cause severe injury or death in animals, has raised alarm about potential financial devastation to Texas ranchers.

Greg Abbott, the Texas governor, issued a disaster proclamation in June to mobilize state resources toward coping with the rising screwworm presence.

Before the pest was reported on American soil, the Trump administration announced the launch of a sterile fly dispersal facility in Edinburg. If female screwworm flies mate with a sterile fly, their offspring will not be viable, thus curbing the population.