The U.S. Food and Drug Administration (FDA) has taken an important regulatory step to address New World screwworm infestations among dogs and puppies. On October 28, 2025, the FDA issued an Emergency Use Authorization (EUA) approving the use of Credelio (lotilaner) chewable tablets for treating infestations caused by this parasitic insect species.
This development is significant for clinical, quality, and regulatory teams involved in animal health and pharmaceutical compliance, offering a new tool to combat a challenging veterinary condition.
What changed?
The FDA’s Emergency Use Authorization brings Credelio (lotilaner) chewable tablets into focus for urgent treatment against New World screwworm infestations in dogs. These infestations, caused by larvae of the parasitic fly Cochliomyia hominivorax, are a serious concern due to their potential to cause severe tissue damage in affected animals.
The approval is based on scientific data suggesting that lotilaner has shown efficacy in treating screwworm infestations. The EUA allows veterinary professionals to offer this treatment option while further comprehensive studies continue in the field.
Scientific findings behind the EUA
Credelio, developed as a chewable tablet, contains lotilaner—an active ingredient known for its ability to target parasite infestations effectively. Lotilaner belongs to the isoxazoline class, recognized for its antiparasitic properties.
Preliminary evidence reviewed by the FDA concluded that Credelio might be effective against New World screwworm infestations. However, the EUA suggests its use is temporary and conditional pending formal regulatory review or clinical study outcomes that confirm its long-term performance and safety profile.
Veterinarians are advised to monitor closely for efficacy and possible side effects, adhering to the manufacturer’s guidelines surrounding administration.
Who is affected?
This authorization directly impacts veterinarians, pharmaceutical teams, and veterinary health organizations. Dog owners in regions prone to New World screwworm infestations may also benefit indirectly as new treatments become available.
Regulatory and quality assurance teams may need to ensure compliance with the EUA conditions, including record-keeping, reporting adverse effects, and monitoring ongoing clinical outcomes.
Organizations involved in veterinary supply chains may also experience increased demand due to the focus on this newly authorized use.
Frequently Asked Questions
1. What is New World screwworm?
New World screwworm refers to infestations caused by the larvae of the parasitic fly Cochliomyia hominivorax, which burrow into open wounds and feed on living tissue.
2. How does lotilaner work against screwworms?
Lotilaner targets nerve receptors in parasites, disrupting their ability to function and leading to effective elimination.
3. Is Credelio fully FDA-approved for screwworm treatment?
No. Credelio has received emergency use authorization, which is a temporary measure pending additional clinical data.
4. Can this treatment be used for other parasitic conditions in dogs?
Yes, Credelio is already FDA-approved for treating fleas and ticks in dogs. Its use for screwworm infestations, however, is specific to the EUA.
5. Are there risks associated with this treatment?
Veterinarians should monitor dogs for side effects and ensure the treatment is used only as directed by the manufacturer’s guidelines.
Conclusion and next steps
The FDA’s Emergency Use Authorization for Credelio (lotilaner) chewable tablets marks an important step in addressing the serious threat posed by New World screwworms in dogs. Veterinary professionals and animal health teams should focus on compliance with EUA conditions while providing the best care possible during this authorization period.
For regulatory professionals, continuous updates from the FDA regarding clinical findings and long-term data are critical.
Disclaimer
This article is informational and targeted toward clinical and regulatory professionals. It is not intended as legal or medical advice. Always consult official regulatory guidance or a qualified professional for assistance with compliance and treatment protocols.
Further reading
For full information about the announcement, see the link below.
http://www.fda.gov/news-events/press-announcements/fda-issues-emergency-use-authorization-new-world-screwworm-drug-dogs