The FDA has expanded emergency use authorization for Dectomax/Dectomax-CA1 (doramectin injection), building on the agency’s September 2025 conditional approval for New World screwworm treatment in cattle by adding dairy cattle, horses, swine, sheep, and deer to the authorized species list as of May 19, 2026.
Summary
- FDA expanded emergency use authorization for Dectomax/Dectomax-CA1 for New World screwworm prevention and treatment.
- The authorization builds on the product’s September 2025 conditional approval for cattle.
- Newly added species include dairy cattle, horses, swine, sheep, and deer.
- Zoetis sponsors Dectomax/Dectomax-CA1.
- FDA issued updated withdrawal periods, milk discard requirements, and species-specific limitations tied to the expanded authorization.
The U.S. Food and Drug Administration has expanded emergency use authorization for Dectomax/Dectomax-CA1 (doramectin injection) as federal agencies continue preparing for potential New World screwworm (NWS) threats affecting livestock and animal health operations.
The May 19 authorization builds on the FDA’s September 2025 conditional approval for Dectomax-CA1 in cattle, significantly expanding the number of species eligible for emergency use treatment and prevention of NWS infestations.
Under the expanded authorization, Dectomax/Dectomax-CA1 may now be used in:
- Dairy cattle
- Horses at least one year old
- Swine
- Sheep excluding lactating sheep
- Deer
According to the FDA, Dectomax remains fully approved for treatment and control of certain parasites in cattle and swine, while Dectomax-CA1 previously received conditional approval specifically for New World screwworm indications in cattle.
The FDA stated that available scientific evidence supports a reasonable belief the product “may be effective” for the authorized indications and that the potential benefits outweigh known and potential risks.
Updated Food Safety Guidance Included
The FDA also issued updated milk discard times and slaughter withdrawal requirements tied to the expanded authorization.
Milk from treated dairy cattle cannot be used for human consumption during treatment and for 468 hours (19.5 days) after treatment.
Slaughter withdrawal periods include:
- Dairy cattle: 35 days
- Swine: 24 days
- Sheep: 35 days
- Deer: 35 days
The agency additionally stated:
- Treated calves and calves born to treated cows cannot be processed for veal.
- The product is not authorized for horses under one year of age or horses intended for human consumption.
- The EUA does not include lactating sheep due to potential milk residue concerns.
Zoetis sponsors Dectomax/Dectomax-CA1.
Additional Resources
- Freedom of Information Summary: Dectomax/Dectomax-CA1 (EUA 006700)
- Letter of Authorization: Dectomax/Dectomax-CA1 (EUA 006700)
- Fact Sheet: Emergency Use Authorization of Dectomax/Dectomax-CA1 for NWS in Dairy Cattle, Swine, Sheep, and Deer
- Fact Sheet: Emergency Use Authorization of Dectomax/Dectomax-CA1 for NWS in Horses
- FDA: Animal Drugs for New World Screwworm
- FDA: Emergency Use Authorization of Animal Drugs for NWS
Information sourced from FDA Center for Veterinary Medicine updates and related agency materials.
