06/26/2026
This afternoon on the second day of the first virtual-only AABP Emerging and Evolving Diseases Conference, Dr. Lewis “Bud” Dinges spoke on “New World Screwworm: Preparedness & current situation”. Dinges is the State Veterinarian and Executive Director at the Texas Animal Health Commission.
New World Screwworm (NWS) epidemiologic principles encompass preventing contact between NWS flies and non-infested animals, and stopping the production cycle of NWS flies.
Dinges says it’s critical to maintain interstate livestock movement, and the Texas response has been to implement “Infested Zone” and movement restrictions with a “Domestic Zoning” concept. And “Infested Zone” is established based on epidemiological assessment. Animals can move out of the “Infested Zone” once they are:
• Inspected and found to be free of wounds and infestation
• Treated with appropriate treatment for that species
• Properly identified.
• Receive a movement permit.
These steps will minimize spread of infestation by human movement of animals and will maximize the effectiveness of sterile flies.
The response includes a commitment to continuity of operations:
• NWS response will NOT require destruction of normal animals or even infested animals that can be treated.
• With rare exception, will not result in the “shut-down” of facilities/operations/premises.
• Producers need to consider what movement restrictions may look like for individual operations.
Communication is essential:
• Producer and Inspector or Certified Inspector or Veterinarian.
• Requires planning and coordination.
o Timing of treatment.
o Timing of inspection – movement permit valid for five days within treatment, three days for untreated slaughter animals.
Animal movement check points:
TAHC animal movement check points set around the perimeter of the Infested Zone.
• Help ensure members of the public are aware of NWS infested zone and are not unintentionally moving infested animals.
• Visible outreach presence for both livestock producers and general public.
• Review animal movement permits to assure movement requirements are met.
NWS treatments:
• FDA and EPA are providing tools for the toolbox.
• Many of the FDA products require a veterinarian prescription to use – urge animal owners to establish a VCPR.
• Other species of livestock and wildlife:
o Extra-label use of current, full-approved products through minor use, minor species (MUMS) and extra-label use.
o Must be under direction (prescription) of a licensed veterinarian and established veterinarian-client-patient relationship (VCPR).
o Establish a VCPR now.
Reporting is critical, Dinges said. It slows the spread caused by movement of infested domestic animals, it helps protect the marketability of the entire state, and it promotes/speeds eradication efforts with sterile flies.
Wound prevention is key. Dinges said producers should take into consideration facilities, handling, animal health management programs, treatment and prevention for induced wounds, treatment and prevention for “natural” wounds, e.g. umbilicus. The best thing to put on animals is eyes – check out all mammals – and monitor, protect and report.
“New World Screwworm is not infectious, it’s a pest,” Dinges said. “It’s not a food safety issue, it’s a production issue.”
Find more information at https://www.tahc.texas.gov/emergency/nws.html.
Registered attendees will have access to the conference recordings within 24 hours; all other AABP members will have access to the recordings on the BCI CE portal at a later date to be announced.
