What Products are Available to Prevent and Treat New World Screwworm?

New World Screwworm or Cochliomyia hominivorax is still south of the U.S. border, but the prevention and treatment playbook is already taking shape. Veterinarians, regulators and ranchers who’ve seen this pest up close keep coming back to the same point: you can’t treat your way out of screwworm.

Prevention means fewer wounds, tighter calving windows, stronger parasite programs and more “eyeballs” on cattle, backed up by early reporting and a vet‑guided treatment plan.

When cases do occur, today’s toolbox — from prescription pour‑ons and emergency‑use injectables — can limit the damage, as long as producers know how and when to use each tool.

The Food and Drug Administration’s (FDA) Center for Veterinary Medicine (CVM) is working with animal drug sponsors to identify potential products and seeks to have them approved or otherwise authorized for the prevention or treatment of NWS myiasis. The agency has multiple regulatory pathways and access mechanisms to facilitate the availability of animal drugs for NWS.

Currently, FDA has conditionally approved two products for use with beef cattle. This list continues to grow as FDA approves products. For an up-to-date list you can visit the FDA website.