Conditional Approval Marks Elanco's Third New World Screwworm Treatment Option for Companion Animals, Providing Multiple Treatment Solutions Prior to Fly Being Detected in the U.S.

• FDA's Conditional Approval of Credelio Quattro-CA1 (lotilaner, moxidectin, praziquantel, and pyrantel chewable tablets) is the first for companion animals against New World screwworm
• Action follows previous Emergency Use Authorizations granted by the FDA for Credelio™ (lotilaner) and Credelio™ CAT (lotilaner) to treat New World screwworm in dogs and cats, respectively
• Credelio Quattro/Credelio Quattro-CA1 provides the broadest parasite coverage of its kind* - covering seven types of parasites including ticks, fleas, heartworm disease, roundworms, hookworms, tapeworms, and now New World screwworm**
• Published literature shows lotilaner, an active ingredient in Credelio Quattro-CA1, has a reasonable expectation of effectiveness for the treatment of infestations caused by New World screwwormⁱ

INDIANAPOLIS , Dec. 18, 2025 /PRNewswire/ -- Elanco Animal Health Incorporated (NYSE: ELAN) today announced it has received conditional approval from the U.S. Food and Drug Administration (FDA) for Credelio Quattro^™-CA1 (lotilaner, moxidectin, praziquantel, and pyrantel chewable tablets) for the treatment of infestations caused by New World screwworm larvae (myiasis) in dogs. This is the first FDA conditional approval for a companion animal product to treat New World screwworm.

Credelio Quattro-CA1 now joins Credelio (lotilaner) and Credelio CAT (lotilaner) on the list of companion animal treatment options for New World screwworm, with these other products recently receiving FDA Emergency Use Authorization for the treatment of New World screwworm infestations in dogs and cats, respectively. According to USDA, there have been 14 cases of New World screwworm within 400 miles of the U.S.-Mexico border, all of them related to cattle movementⁱⁱ. With detection reaching as close as 70 miles south of the U.S.-Mexico borderⁱⁱⁱ, veterinarians and pet owners now have multiple treatment options available should the fly enter the U.S.

"We appreciate the FDA's commitment to preparing and providing treatment options for New World screwworm in advance of the fly entering the U.S.," said Dr. Ellen DeBrander, Executive Vice President of Research & Development at Elanco. "Elanco's Credelio family of brands has made significant strides in animal health and this conditional approval for treatment of New World screwworm in dogs now allows us to provide multiple treatment solutions for veterinarians, animal shelters, and pet owners should they need it urgently."

The conditional approval was based on a study evaluating the efficacy of lotilaner, the active ingredient in Credelio Quattro-CA1, against New World screwworm. In the peer-reviewed study, published in Parasites & Vectors, oral administration of lotilaner at the minimum recommended dosage demonstrated 100% efficacy against Cochliomyia hominivorax (New World screwworm) larvae within 24 hours of treatment in naturally infested dogs.ⁱ

According to the FDA, a conditionally approved animal drug has been shown to be safe and has a reasonable expectation of effectiveness.

Veterinarians and consumers will see new product labeling in 2026 that reflects the conditions of use for both Credelio Quattro and Credelio Quattro-CA1 on the same packaging.

Credelio Quattro/Credelio Quattro-CA1 Provides 7 in 1 Coverage**

Credelio Quattro provides the broadest* parasite protection in a monthly chewable tablet, covering six types of parasites including ticks, fleas, and heartworm disease and three types of intestinal parasites – roundworms, hookworms, and tapeworms. Now with conditional approval for the treatment of New World screwworm infestations, Credelio Quattro/Credelio Quattro-CA1 provides 7 in 1 parasite coverage**, providing veterinarians and pet owners with another option should the fly enter the country.

Elanco remains committed to proactive life cycle management of the Credelio Quattro brand, and today's milestone represents the third positive label advancement achieved in under 11 months since launch. In May, the Credelio Quattro label was updated to include an additional species of hookworm (Ancylostoma caninum), and in October FDA approved an expanded label to include prevention of Lyme disease as a result of killing black-legged ticks and protection against the longhorned tick, which is rapidly spreading, now reaching 22 states.^iv

While livestock are most commonly affected, New World screwworm can infest all warm blooded animals – including pets, wildlife, and even humans.

"As a veterinarian, I'd encourage pet owners to monitor for any wounds on their dogs as even a minor scratch could serve as an entry point for New World screwworm," said Dr. Casey Locklear, parasitology lead at Elanco. "I also recommend pet owners keep their dogs on year-round parasite protection like Credelio Quattro to help minimize self-inflicted scratching that could create vulnerable sites."

Learn more about Credelio Quattro/Credelio Quattro-CA1 here.

To learn more about New World screwworm, the following resources are available:

• Stop Screwworm: Unified Government Response to Protect the United States 
• FDA Information for Veterinarians on New World Screwworm 
• USDA NWS Alert and Fact Sheet

*Based on label comparison of the number of parasite types covered in a chewable that targets ticks
**Credelio Quattro protects dogs against ticks, fleas, heartworm disease, roundworms, hookworms, and tapeworms. Credelio Quattro-CA1 is conditionally approved for the treatment of New World screwworm larvae infestations in dogs pending a full demonstration of effectiveness.

ABOUT ELANCO

Elanco Animal Health Incorporated (NYSE: ELAN) is a global leader in animal health dedicated to innovating and delivering products and services to prevent and treat disease in farm animals and pets, creating value for farmers, pet owners, veterinarians, stakeholders, and society as a whole. With 70 years of animal health heritage, we are committed to breaking boundaries and going beyond to help our customers improve the health of animals in their care, while also making a meaningful impact on our local and global communities. At Elanco, we are driven by our vision of Food and Companionship Enriching Life and our purpose – all to Go Beyond for Animals, Customers, Society, and Our People. Learn more at www.elanco.com.

Indications for Credelio Quattro/Credelio Quattro-CA1

Credelio Quattro is indicated for the prevention of heartworm disease and the treatment and control of roundworm, hookworm, and tapeworm infections. Credelio Quattro kills adult fleas and is indicated for the treatment and prevention of flea infestations and the treatment and control of tick infestations for 1 month in dogs and puppies 8 weeks of age and older and weighing 3.3 pounds or greater. Credelio Quattro is indicated for the prevention of Lyme disease infections as a direct result of killing black-legged ticks.

Credelio Quattro-CA1 is conditionally approved for the treatment of infestations caused by New World screwworm (NWS) larvae in dogs and puppies 8 weeks of age and older and weighing 3.3 pounds or greater.

Important Safety Information for Credelio Quattro/Credelio Quattro-CA1

Lotilaner, an ingredient in Credelio Quattro/Credelio Quattro-CA1, belongs to the isoxazoline class and has been associated with neurologic adverse reactions like tremors, incoordination, and seizures even in dogs without a history of seizures. Use with caution in dogs with a history of seizures or neurologic disorders. Dogs should be tested for existing heartworm infections before Credelio Quattro/Credelio Quattro-CA1 administration as it is not effective against adult heartworms. The safe use in breeding, pregnant, or lactating dogs has not been evaluated. The most frequently reported adverse reactions in clinical trials were vomiting and diarrhea.

Credelio Quattro-CA1 is conditionally approved by the FDA pending a full demonstration of effectiveness under application number 141-619. If you suspect that your dog is infested with NWS larvae, seek veterinary care immediately for treatment to include removal of larvae and appropriate wound care.

For complete safety information, please see the Credelio Quattro/Credelio Quattro-CA1 product label or ask your veterinarian.

Emergency Use Authorization for Credelio (lotilaner) for New World Screwworm (NWS)

The U.S. Food and Drug Administration (FDA) has issued an Emergency Use Authorization (EUA) for the emergency use of the approved product Credelio (lotilaner) for the treatment of infestations caused by NWS (Cochliomyia hominivorax) larvae (myiasis) in dogs and puppies. However, Credelio is not approved for this use.

Credelio is approved for other uses.

For additional information on the EUA, please refer to the Credelio NWS Fact Sheet.

Limitations of Authorized Use

Credelio (lotilaner) is authorized only for the duration of the declaration that circumstances exist justifying the authorization of the emergency use of Credelio (lotilaner) under section 564(b)(1) of the Federal Food, Drug, and Cosmetic Act (FD&C Act), 21 U.S.C. § 360bbb-3(b)(1), unless the authorization is terminated or revoked sooner.

Indications for Credelio

Credelio kills adult fleas and is indicated for the treatment and prevention of flea infestations and treatment and control of tick infestations (lone star tick, American dog tick, black-legged tick, brown dog tick, and longhorned tick) for one month in dogs and puppies 8 weeks and older and 4.4 pounds or greater. Credelio is indicated for the prevention of Lyme disease infections as a direct result of killing black-legged ticks.

Important Safety Information for Credelio

Lotilaner is a member of the isoxazoline class of drugs. This class has been associated with neurologic adverse reactions including tremors, incoordination, and seizures. Seizures have been reported in dogs receiving this class of drugs, even in dogs without a history of seizures. Use with caution in dogs with a history of seizures or neurologic disorders. The safe use of Credelio in breeding, pregnant or lactating dogs has not been evaluated. The most frequently reported adverse reactions are weight loss, elevated blood urea nitrogen, increased urination, and diarrhea. For complete safety information, please see Credelio product label or ask your veterinarian.

Emergency Use Authorization for Credelio CAT (lotilaner) for New World Screwworm (NWS)

The U.S. Food and Drug Administration (FDA) has issued an Emergency Use Authorization (EUA) for the emergency use of the approved product Credelio CAT (lotilaner) for the treatment of infestations caused by NWS (Cochliomyia hominivorax) larvae (myiasis) in cats and kittens. Credelio CAT is not approved for this use.

Credelio CAT is approved for other uses.

For additional information on the EUA, please refer to the Credelio Cat NWS Fact Sheet.

Limitations of Authorized Use

Credelio CAT (lotilaner) is authorized for this use only for the duration of the declaration that circumstances exist justifying the authorization of the emergency use of Credelio CAT (lotilaner) under section 564(b)(1) of the Federal Food, Drug, and Cosmetic Act (FD&C Act), 21 U.S.C. § 360bbb-3(b)(1), unless the authorization is terminated or revoked sooner.

Indications for Credelio CAT

Credelio CAT kills adult fleas and is indicated for the treatment and prevention of flea infestations for one month in cats and kittens 8 weeks of age and older and weighing 2 pounds or greater.

Credelio CAT is also indicated for treatment and control of black-legged tick infestations for one month in cats and kittens 6 months of age and older and weighing 2 pounds or greater.

Important Safety Information for Credelio CAT

Lotilaner is a member of the isoxazoline class of drugs. This class has been associated with neurologic adverse reactions including tremors, incoordination and seizures. Neurologic adverse reactions have been reported in cats receiving isoxazoline class drugs, even in cats without a history of neurologic disorders. Use with caution in cats with a history of neurologic disorders. The safety of Credelio CAT has not been established in breeding, pregnant and lactating cats. The effectiveness of Credelio CAT against black-legged ticks in kittens less than 6 months of age has not been evaluated. The most frequently reported adverse reactions are weight loss, rapid breathing and vomiting. For complete safety information, please see Credelio CAT product label or ask your veterinarian.

Credelio, Credelio Quattro, Elanco and the diagonal bar logo are trademarks of Elanco or its affiliates. © 2025 Elanco or its affiliates

PM-US-25-2404

ⁱ d do Vale, T.L., Costa, A.R., Miranda, L.M. et al. Efficacy of lotilaner against myiasis caused by Cochliomyia hominivorax (Diptera: Calliphoridae) in naturally infested dogs. Parasites Vectors 16, 86 (2023). https://doi.org/10.1186/s13071-023-05661-z
ⁱⁱ US Department of Agriculture . (n.d.). Current Status of New World Screwworm in the United States. https://www.aphis.usda.gov/livestock-poultry-disease/stop-screwworm/current-status
ⁱⁱⁱMexico Confirms Case of New World Screwworm in Nuevo Leon | Animal and Plant Health Inspection Service
^iv Triltsch, O. (2025, August 28). Tiny invaders: The rise of the Asian longhorned tick. Michigan United Conservation Clubs: Join Us Today! https://www.mucc.org/tiny-invaders-the-rise-of-the-asian-longhorned-tick

Investor Contact: Tiffany Kanaga (765) 740-0314 tiffany.kanaga@elancoah.com
Media Contact: Season Solorio (765) 316-0233 season.solorio@elancoah.com 

 

View original content to download multimedia:https://www.prnewswire.com/news-releases/elancos-credelio-quattro-ca1-lotilaner-moxidectin-praziquantel-and-pyrantel-chewable-tablets-receives-first-fda-conditional-approval-for-treatment-of-new-world-screwworm-in-dogs-302645913.html

SOURCE Elanco Animal Health