Rising spring temperatures are bringing increased concern about New World screwworm potentially crossing into the United States from Mexico. The National Milk Producers Federation is collaborating with government agencies and industry partners to help dairy operations prepare for this threat.
Active infestations are moving northward toward the border between the US and Mexico, with the nearest confirmed case approximately 150 miles south of Texas. In response, officials are deploying sterile flies within 50 miles of the Mexican border in Texas to control pest populations before they can affect American cattle operations.
On March 16, the National Milk Producers Federation hosted an educational webinar featuring key experts to discuss the latest developments regarding New World screwworm and its potential impact on American dairy operations.
The webinar featured three specialists: Dr. Adis Dijab from APHIS Veterinary Services as associate deputy administrator, Dr. Sonja Swiger who serves as professor and extension entomologist at Texas A&M AgriLife Extension, and Dr. T.R. Lansford III, who holds positions as deputy executive director and assistant state veterinarian with the Texas Animal Health Commission. These experts explained how to identify screwworm symptoms in cattle, provided updates on the pest’s current distribution, and offered actionable prevention strategies for producers.
The specialists also outlined available treatment protocols for affected livestock and explained possible cattle transportation regulations or limitations that could be implemented if an outbreak occurs within US borders.
Federal USDA officials and state authorities will lead outbreak response efforts. The National Milk Producers Federation has submitted recommendations to USDA’s Animal and Plant Health Inspection Service regarding their emergency response strategies for potential US screwworm invasions, and USDA is incorporating this input into their updated response framework.
Should an outbreak occur, USDA will oversee interstate animal movement, while individual states may implement additional regulations for livestock transportation within their boundaries. Producers should anticipate quarantine measures and movement limitations in areas near any infestation, including mandatory pre-transport health examinations and treatment protocols when necessary, following established continuity of business guidelines for screwworm animal health certification. Most producers should retain the ability to transport their animals by following protocols for inspections, wound care, documentation, and proper biosecurity measures.
The FDA has broadened treatment options for New World screwworm through Emergency Use Authorizations. On March 10, FDA approved an EUA for a new topical spray specifically for lactating dairy cattle that requires only a 10-day milk withdrawal period. This represents the first approved medication for treating New World screwworm in milk-producing cattle.
The National Milk Producers Federation plans to maintain its collaboration with federal and state officials to ensure dairy producers receive necessary resources and assistance to maintain healthy herds.
