The LSU School of Veterinary Medicine is encouraging pet owners, livestock producers, horse owners, and veterinarians to remain vigilant following the recent detection of New World screwworm (NWS) confirmed cases in Texas and New Mexico.
What is NWS?
New World screwworm is a parasitic fly whose larvae, commonly known as maggots, feed on the living tissue of warm-blooded animals. Unlike most maggots that feed on dead tissue, screwworm larvae burrow into healthy flesh, causing painful wounds, severe infections, and, if left untreated, death. The pest can affect livestock, horses, wildlife, dogs, cats, and, in rare cases, people.
Currently, there are no confirmed cases of New World screwworm in Louisiana, but awareness and early detection are critical. Animal owners should routinely inspect their animals for wounds and seek veterinary care immediately if they notice anything unusual.
Government Response
The U.S. Department of Agriculture and Texas animal health officials are actively responding to the detection through quarantines, surveillance, movement controls, and the release of sterile male screwworm flies to help stop the pest's spread.
According to the Louisiana Department of Agriculture and Forestry, additional animal movement requirements are being implemented to reduce the risk of the pest entering Louisiana. These measures include enhanced health certificate requirements for certain animals entering the state from Texas, specifically lowering the validity of health certificates for animals entering Louisiana from 30 to seven days. Learn more at ldaf.la.gov.
What to Look For
Screwworm larvae most commonly enter through open wounds, surgical incisions, tick bites, the navels of newborn animals, or natural body openings such as the nose, ears, eyes, and genital regions.
Animal owners should watch for:
- Wounds that fail to heal
- Bloody or foul-smelling discharge from wounds
- Visible maggots or egg masses in wounds or body openings
- Excessive licking, chewing, or irritation around a wound
- Signs of discomfort, depression, or reduced appetite
There are currently no vaccines available to prevent New World screwworm. Rapid detection and response remain the most effective tools for preventing its spread.
Diagnosis
LSU Diagnostics (Louisiana Animal Disease Diagnostic Laboratory) is working with the Louisiana State Animal Health Officials (SAHO) for identification of all suspected cases. All confirmatory testing and reporting are being performed by the National Veterinary Services Laboratories, which will communicate results to the SAHO.
What to Do if You Suspect NWS
Animal owners who suspect New World screwworm should contact their veterinarian and the State Animal Health Official (SAHO) immediately at vetreports@ldaf.state.la.us or 225-925-3980. In Louisiana, the SAHO is Louisiana State Veterinarian Dr. Daniel Myrick (LSU 2001) with the Louisiana Department of Agriculture and Forestry.
The public should be aware that New World screwworm does not affect the safety of the U.S. food supply. Federal inspection programs are designed to identify affected animals and prevent contaminated products from entering commerce.
For more information about New World screwworm, visit Screwworm.gov or the LSU AgCenter webpage on NWS.
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The LSU School of Veterinary Medicine is one of only 33 veterinary schools in the U.S. and the only one in Louisiana. LSU Vet Med is dedicated to improving and protecting the lives of animals and people through superior education, transformational research, and compassionate care. We teach. We heal. We discover. We protect.