As the New World Screwworm (NWS) continues to make headlines, it is important to be aware of your herd’s risk level. Producers need to be prepared to implement additional monitoring and biosecurity measures if an infestation occurs in their area. Dr. Mitch Blanding, the director of beef technical services at Zoetis, discussed steps producers can take to prepare for a potential NWS incursion.
Unfortunately, New World Screwworm poses serious welfare and economic risks for U.S. livestock producers. Producers should be prepared to report a New World Screwworm incursion as quickly as possible and follow USDA-aligned wound protocols with their veterinarian.
Proactive Herd Management and Veterinary Protocols
Any cattle producer in close geographic proximity to a screwworm incident or where an infestation is likely to occur should work closely with their herd veterinarian to determine risk levels and assess any potential adjustments to management practices.
Producers are also encouraged to work closely with their veterinarians to implement written plans. The industry objective is to document and isolate these cases, clean and debride wounds where possible, remove easily removed larvae, and apply approved topicals. Managing animal pain throughout this process is another critical component.
Emergency Use Authorization and Treatment Options
Dr. Blanding highlighted the treatment options available for managing screwworm infestations, noting that Dectomax and Dectomax CA1 have been granted an Emergency Use Authorization (EUA) by the U.S. Food and Drug Administration (FDA) for dairy cattle, horses, swine, sheep, and deer.
The FDA issued the EUA for Dectomax and Dectomax CA1 for specific indications:
- Dairy Cattle: For the prevention and treatment of infestations caused by New World Screwworm larvae. This includes lactating dairy cows with a 468-hour milk withdrawal period, dry dairy cows, and replacement dairy heifers 20 months of age and older. It is not approved to process calves for veal.
- Swine, Sheep, and Deer: For the prevention of infestations caused by New World Screwworm larvae, excluding lactating sheep.
- Horses: For the prevention of infestations caused by New World Screwworm larvae in horses one year of age and older.
Accessing Resources and Reporting
For more information on New World Screwworm and the current conditional approval and emergency use authorization for Dectomax and Dectomax CA1, producers can visit zoetisus.com/newworldscrewworm.
Industry stakeholders should also refer to the USDA New World Screwworm response playbook and contact their veterinarian, state animal health official, or USDA APHIS to report any suspected infestations.
Important Information: Dectomax-CA1 Injectable (Cattle only), as authorized under the Conditional Approval for use against New World screwworm, has a 35-day pre-slaughter withdrawal period. Do not use in calves to be processed for veal. Do not use in female dairy cattle 20 months of age or older, except under the conditions of the Emergency Use Authorization. Use in dogs may result in fatalities.
Dectomax/Dectomax CA1 Injectable Emergency Use Authorization, authorized for the duration of the emergency declaration, does not provide full or conditional approval, but the Center for Veterinary Medicine (CVM) at the Food and Drug Administration (FDA) has determined that Dectomax/Dectomax CA1 may be effective and safe.
Dectomax/Dectomax-CA1 Injectable, as authorized under the Emergency Use Authorization for use against New World screwworm, has a 35-day pre-slaughter withdrawal period for lactating dairy cattle, dry dairy cattle, replacement dairy heifers, sheep and deer, and a 24-day pre-slaughter withdrawal period for swine. Treated calves and calves born to treated cows should not be processed for veal. Withhold milk from dairy cattle for 468 hours (19.5 days) after treatment has ended. Not for use in lactating sheep. Not for use in horses less than 1 year of age. Consult your veterinarian for assistance in the diagnosis, treatment, and control of parasitism. Review the fact sheets and see full prescribing information at zoetisus.com/NewWorldscrewworm.”
