Indiana animal health officials have imposed new restrictions on livestock, poultry and pet movements from parts of the Southwest following the recent detection of New World screwworm in the United States, as states across the country work to prevent the destructive parasite from gaining a foothold beyond currently affected areas.
The Indiana State Board of Animal Health announced that animals entering Indiana from federally designated New World screwworm-infested zones — currently parts of Texas and New Mexico — will be subject to enhanced inspection, treatment and certification requirements.
The measures come after the U.S. Department of Agriculture confirmed cases of the pest in the United States, raising concerns among livestock producers and animal health officials about the potential for the parasite to spread through animal movements, exhibitions and travel.
Although New World screwworm has not been detected in Indiana, state officials warned that the insect could be inadvertently transported by animals or people traveling from affected regions.
“The latest findings have triggered movement restrictions for animals traveling to Indiana from NWS-infested areas,” the agency said in an advisory issued Monday.
Under the new requirements, livestock and companion animals originating from an infested zone must be inspected by a USDA-accredited veterinarian within five days before shipment and accompanied by a certificate of veterinary inspection. Animals also must receive approved treatments designed to prevent the spread of screwworm before entering Indiana.
Additional documentation approved by both the state of origin and Indiana animal health officials will be required before shipment.
The restrictions apply broadly to cattle, horses, sheep, goats, swine, poultry, dogs and cats, although Indiana has carved out exemptions for certain poultry shipments, indoor-housed small mammals and some commercial swine operations operating under approved health plans.
The Indiana State Board of Animal Health said it has been coordinating for more than a year with the Indiana Department of Health and the Indiana Department of Natural Resources on response plans should the parasite move closer to the Midwest.
New World screwworm, despite its name, is not a worm but the larval stage of a fly. Adult female flies lay eggs in open wounds or natural body openings of warm-blooded animals. Once hatched, the larvae burrow into living tissue, feeding on flesh and causing wounds to expand and deepen. Untreated infestations can lead to severe injury and death.
Livestock producers are particularly concerned because the pest can affect cattle, sheep, goats, horses, swine and other animals. Pets and wildlife are also susceptible, and in rare cases humans can become infested.
The United States eradicated New World screwworm in 1966 through an extensive sterile fly release program, one of the most successful insect control campaigns ever undertaken. Federal and Mexican animal health authorities continue to use that strategy today, releasing sterile male flies to disrupt reproduction and suppress populations.
USDA recently expanded sterile fly production efforts in Texas as part of its response to the current outbreak.
Indiana officials are urging animal owners to closely monitor livestock, poultry and pets for signs of infestation, particularly after travel or participation in exhibitions.
Warning signs include unusual flies or maggots around wounds, ears, noses or other body openings; wounds that continue to enlarge or drain; foul odors associated with infected tissue; and animals exhibiting signs of irritation or discomfort.
The adult New World screwworm fly can be identified by its metallic blue-green body, orange eyes and three dark stripes running down its back.
State officials are asking veterinarians, livestock producers and pet owners to immediately report suspicious cases.
“Inspect, report and protect” is the message Indiana officials are emphasizing as they seek to keep the parasite from reaching the state’s farms and animal populations.
Additional information and reporting resources are available through the Indiana State Board of Animal Health at: www.in.gov/boah/.
