Dairy farmers across the nation are being urged to prepare for a potential outbreak of New World screwworm after Mexican authorities documented more than 1,200 cases during May. The closest confirmed infection sits approximately 31 miles from the United States border, leading agricultural experts to warn that an American outbreak could happen soon.
The parasite poses a serious threat to livestock by creating severe wounds that may result in death, making early detection by farmers crucial for prevention and treatment efforts. Federal regulators have responded by expanding the list of medications available to combat the pest through emergency and conditional approvals.
The Food and Drug Administration took action on May 19 by issuing an emergency use authorization for doramectin injection, known as Dectomax-CA1, allowing its use in lactating and dry dairy cows along with replacement heifers 20 months and older. This medication had already received conditional approval for younger female dairy cattle under 20 months, but the emergency authorization broadens treatment options for producers facing a potential outbreak.
The FARM Antibiotic Stewardship Program, which stands for Farmers Assuring Responsible Management, has published guidance containing details about currently approved and authorized treatments for New World screwworm. This resource aims to help farmers make informed decisions that safeguard their livestock while ensuring responsible antimicrobial usage.
Federal agriculture officials have established a comprehensive five-part strategy emphasizing rapid detection, treatment and containment measures, livestock movement restrictions, and investment in innovative treatment and control methods. Industry organizations have participated in coordination meetings with federal and state officials to establish effective prevention practices and have endorsed a registration application for NovoFly that was submitted on April 22.
Farmers who believe they may have infected animals should immediately contact their veterinarian to file a report, obtain samples for laboratory testing, and receive treatment guidance. Federal agriculture officials have established an informational website that offers current updates and information about confirmed cases.
Once the screwworm enters American territory, farmers should anticipate movement restrictions in affected regions, including mandatory inspections and treatments to prevent further spread. Agricultural producers are advised to collaborate with their veterinarians and coordinate with state animal health authorities regarding movement protocols.
