A horse in Presidio County, Texas, has tested positive for New World screwworm in what officials say is the first confirmed equine case in the United States this century.
The parasite was identified on the hind leg of a working ranch horse on 9 September, according to the United States Equestrian Federation. The case forms part of the current outbreak of the flesh-eating pest in the southern US.
New World screwworm larvae burrow into wounds and feed on the living tissue of warm-blooded animals. Infestations can affect livestock, wildlife and, in rare cases, people.
Horse owners urged to check animals daily
Horse owners have been advised to inspect their animals every day for wounds, swelling, fluid drainage, foul smells or maggots.
Particular attention should be paid to small cuts, surgical sites, the umbilical area of foals and moist areas around the lips, nostrils, eyes and genital regions. Any suspected infestation should be reported to a vet immediately.
The Texas Animal Health Commission says movement restrictions are in place in parts of several counties, including Presidio and neighbouring areas. Warm-blooded animals cannot be moved out of an affected zone without prior authorisation or inspection.
New World screwworm was first detected in Texas during the current outbreak on 3 June, when a calf in Zavala County tested positive. The Texas Animal Health Commission says cases have since been recorded across 17 counties.
The adult fly resembles other common flies but has large orange eyes, a yellow face, a metallic blue body and three dark stripes along its back. Authorities are using surveillance and sterile-fly releases as part of efforts to contain the spread.
