Nine weeks after USDA confirmed New World screwworm in a three-week-old calf in Zavala County, Texas, the United States now has a third EUA-backed veterinary tool in its outbreak response: Elanco’s CLiK Extra (dicyclanil topical suspension) wound spray, authorized by FDA on August 7, 2026. That timeline matters because dicyclanil works differently from the earlier authorizations, and the gap it fills is specific: prophylaxis, not rescue.
CLiK Extra is authorized for application on or around wounds in sheep, cattle, goats, swine, camelids, and several captive and captured wildlife species including American bison, bighorn sheep, and Sonoran pronghorn. The critical constraint is explicit in the authorization language: the product prevents infestations but does not treat an active one. If larvae are already present when the spray is applied, producers must reach for something else. Elanco’s Negasunt Powder, which received its EUA on April 27, 2026, covers both prevention and treatment, while Catron IV, an EPA-registered permethrin-based spray, addresses kill and control of screwworm flies and maggots in several livestock species. The product roles are distinct, and producers conflating them risk serious animal welfare consequences.
CLiK Extra’s distribution channel adds another layer of strategic complexity. Unlike Catron IV, which moves through conventional commercial channels, both CLiK Extra and Negasunt Powder flow exclusively through USDA’s Animal and Plant Health Inspection Service and its National Veterinary Stockpile, distributed in coordination with state animal health officials and federally recognized tribal agencies. That centralized supply chain limits how quickly individual producers can access the product independently, placing real weight on the “eyes on livestock” protocol: wounds identified late cannot be treated preventively with CLiK Extra. The 86-day pre-slaughter withdrawal period for most treated ruminants adds a further planning burden for beef producers operating near processing schedules.
The metric worth tracking here is how rapidly APHIS can move CLiK Extra inventory into the hands of producers in and around the confirmed Texas outbreak zone, because the prevention window for any given wound is measured in hours, not days. Distribution velocity, not authorization status, is now the binding constraint on whether this EUA translates into meaningful outbreak containment.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
