The U.S. Food and Drug Administration issued an Emergency Use Authorization for CLiK Extra wound spray on August 7, 2026. Sponsored by Elanco US Inc., the topical suspension prevents New World screwworm myiasis in sheep, cattle, goats, swine, camelids, and specific captive wildlife species, providing a defense against the parasitic fly larvae.
In Plain English: The Clinical Takeaway
- What it is: CLiK Extra is an over-the-counter topical wound spray containing dicyclanil, functioning as an insect growth regulator rather than a direct insecticide.
- Mechanism of Action: Instead of killing existing larvae, the drug disrupts insect development, halting the lifecycle of the New World screwworm before tissue damage occurs.
- Usage Parameters: It is authorized strictly for prevention on or around wounds, birth sites, or surgical procedures like dehorning and castration, but cannot treat an active infestation.
Regulatory Action and Species Scope Under the Emergency Use Authorization
Acting FDA Commissioner Kyle Diamantas, J.D., emphasized the necessity of expanding protective options for agricultural and wildlife sectors alike. Under the federal declaration, the authorization extends beyond traditional livestock—such as cattle, sheep, goats, swine, and camelids like llamas and alpacas—to encompass captive and captured wildlife populations. According to the FDA announcement, eligible wildlife species include cervids like deer and elk, American bison, bighorn sheep, and Sonoran pronghorn.
Timothy Schell, Ph.D., director of the FDA’s Center for Veterinary Medicine, noted that the scope of New World screwworm impact reaches far beyond standard farm boundaries. Authorizing the dicyclanil topical suspension for vulnerable wildlife helps ensure these species do not contribute to the spread of NWS in the United States. The emergency framework relies on the totality of available scientific evidence, establishing that the known and potential benefits of the wound spray outweigh any associated risks.
Pharmacological Mechanism and Clinical Application Boundaries
Understanding how dicyclanil operates requires looking closely at its physiological classification. Acting as an insect growth regulator, dicyclanil interferes with larval development, stopping their lifecycle prematurely to protect the host animal from tissue harm.
Clinical precision is paramount for veterinarians and livestock managers utilizing this emergency authorization. The FDA stipulates that CLiK Extra is indicated exclusively for the prevention of myiasis associated with fresh wounds, birth, or husbandry procedures including ear tagging, tail docking, shearing, and castration. Application must coincide with the appearance or creation of the wound. Crucially, the regulatory agency stresses that if a wound is already infested, or if an infestation develops despite administration, the product is ineffective for treatment, and professionals must intervene immediately.
| Parameter | Clinical Details |
|---|---|
| Product Name | CLiK Extra (dicyclanil topical suspension) |
| Sponsor | Elanco US Inc. (Indianapolis, Indiana) |
| Regulatory Mechanism | FDA Emergency Use Authorization (EUA) issued August 7, 2026 |
| Pharmacological Class | Insect Growth Regulator (IGR) |
| Target Species | Sheep, cattle, goats, swine, camelids, and designated captive wildlife (cervids, bison, bighorn sheep, Sonoran pronghorn) |
| Primary Indication | Prevention of New World screwworm (NWS) myiasis on or around wounds |
Public Health Stakes and Epidemiological Surveillance
The arrival of emergency authorizations for treatments like CLiK Extra reflects federal responses coordinated alongside the U.S. Department of Health and Human Services. The New World screwworm is a parasitic fly whose larvae feed on the living tissue of warm-blooded animals.
By deploying insect growth regulators directly onto vulnerable tissue sites during routine husbandry, producers interrupt the transmission cycle at the individual animal level.
Contraindications & When to Consult a Doctor
CLiK Extra wound spray carries strict operational boundaries that must be observed by handlers, veterinarians, and agricultural managers:
- Active Infestation Contraindication: Do not use this product to treat animals that already exhibit active screwworm larva infestation within the wound.
- Veterinary Consultation: If an animal develops myiasis after application, or if larvae are discovered upon initial examination, immediately contact a licensed veterinarian to discuss appropriate therapeutic treatment options.
- Food Safety Compliance: Users must adhere strictly to the detailed food safety information outlined in the official FDA Emergency Use Authorization Fact Sheet before sending treated livestock to market.
Future Trajectory and Regulatory Longevity
The emergency use authorization remains active until explicitly revoked by the FDA or until the Secretary of Health and Human Services terminates the underlying public health emergency declaration. While over-the-counter availability simplifies immediate access for ranchers and wildlife managers, ongoing surveillance remains essential. As regulatory bodies evaluate additional countermeasures, integrating targeted chemical preventatives like dicyclanil into standard herd health programs ensures a defense against parasitic encroachment.
References
- U.S. Food and Drug Administration (FDA). FDA Issues Emergency Use Authorization for Drug to Prevent New World Screwworm in Multiple Species, Including Cattle and Sheep. Published August 7, 2026.
- U.S. Food and Drug Administration (FDA) Center for Veterinary Medicine. Fact Sheet: Emergency Use Authorization of CLiK Extra (dicyclanil topical suspension) Wound Spray for New World Screwworm (NWS).
This reporting does not constitute veterinary or medical advice. Always consult a licensed veterinarian or qualified agricultural extension specialist regarding animal health management and treatment protocols.
