Elanco Animal Health Commits to Supporting U.S. Livestock Producers and Pet Owners in Fight Against New World Screwworm

Company offers portfolio of treatment options and expert guidance following first confirmed case in the United States 

• New World screwworm has officially reached the United States, with the first confirmed case in U.S. livestock in Texasⁱ 
• New World screwworm can infest any warm-blooded animals – including livestock and pets – posing a significant threat to animal health, welfare, and producer livelihood 
• Elanco offers a portfolio of options for both livestock and pets that can treat infestations caused by New World screwworm larvae 

INDIANAPOLIS , June 4, 2026 /PRNewswire/ -- Elanco Animal Health Incorporated (NYSE: ELAN) today reaffirms its commitment to providing veterinarians, livestock producers, and pet owners with resources and treatment options for their animals against the escalating threat posed by New World screwworm (NWS). The fly recently reached the United States, with the first case confirmed in U.S. livestock in Texas.ⁱ 

The emergence of New World screwworm in the U.S. creates a threat for veterinarians, livestock producers and pet owners that has not been seen north of the Florida Keys since the fly was eradicated from the United States more than 50 years ago.ⁱⁱ New World screwworm (Cochliomyia hominivorax) larvae feed on living tissue and can affect a wide range of warm-blooded animals, including livestock, companion animals, wildlife, and even humans.ⁱⁱ 

"New World screwworm could have a devastating impact on animal health, welfare, and producer livelihoods," said Jeff Simmons, President and CEO, Elanco Animal Health. "We want to thank the FDA, EPA and USDA, for all their work to prepare for this threat. We're committed to supporting our customers during this challenging time by delivering innovation, scientific expertise, and available resources to help treat New World screwworm and support the health and well-being of animals." 

With more than 70 years of animal health experience, including helping mitigate, prevent and treat New World screwworm in other parts of the world, Elanco is working alongside the U.S. animal health industry to help them fight against this parasite, offering a portfolio of options for pets and livestock that can help treat New World screwworm larvae infestations. 

Available Elanco Treatment and/or Prevention Options  

Negasunt Powder and Tanidil will be available only through the U.S. Animal Plant Health and Inspection Service (APHIS) and its National Veterinary Stockpile. They will be distributed in coordination with state animal health officials and federally recognized tribal agencies. In the near future, APHIS will share additional information about the requirements for use, including tracking and reporting requirements and required safety and personal protective equipment. 

As New World screwworm enters the United States, Elanco is committed to working alongside producers as they continuously evolve management practices and to help them implement prevention and treatment protocols to use the right product at the right time. 

To learn more about Elanco's ongoing efforts and historical perspective on New World screwworm, please visit our previous coverage: 

• Elanco's Negasunt™ Powder (Coumaphos, Propoxur, Sulfanilamide Topical Powder) and Tanidil™ (Coumaphos, Propoxur) Receive Emergency Authorization for Use Against New World Screwworm in Livestock 
• Elanco's Credelio Quattro™-CA1 (lotilaner, moxidectin, praziquantel, and pyrantel chewable tablets) Receives First FDA Conditional Approval for Treatment of New World Screwworm in Dogs 
• Elanco's Credelio™ CAT (lotilaner) Receives First FDA Emergency Use Authorization (EUA) for Treatment of New World Screwworm (NWS) in Cats 
• Elanco's Credelio™ (lotilaner) Receives First Ever FDA Emergency Use Authorization (EUA) against New World Screwworm (NWS) in Dogs 

To learn more about New World screwworm (NWS) using the following resources: 

• USDA NWS Alert and Fact Sheet 
• NCBA NWS Resources 
• FDA Information for Veterinarians on NWS 

About Elanco Animal Health 

Elanco Animal Health Incorporated 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 of Credelio (lotilaner) Chewable Tablets 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) chewable tablets for the treatment of infestations caused by NWS (Cochliomyia hominivorax) larvae (myiasis) in dogs and puppies. Credelio is not approved for this use. 

Credelio (lotilaner) is approved for other uses in dogs and puppies. 

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

Limitations of Authorized Use 

Credelio (lotilaner) chewable tablets is authorized for this use only for the duration of the declaration that circumstances exist justifying the authorization of the emergency use of Credelio (lotilaner) chewable tablets 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. 

Emergency Use Authorization of Negasunt Powder (coumaphos, propoxur, and sulfanilamide topical powder) for New World Screwworm (NWS) 

WARNING: Neurotoxicity. Read full Fact Sheet for complete information. 

• Coumaphos and propoxur can cause neurotoxicity. May be fatal if swallowed. May be fatal if inhaled. Harmful if absorbed through skin. Causes moderate eye irritation. Do not breathe dust. Avoid contact with eyes, skin, or clothing. 
  
  
• Use only with appropriate personal protective equipment (PPE): coveralls worn over long-sleeve shirt and long pants, shoes, socks, and protective eyewear; chemical-resistant gloves made of  barrier laminate, butyl rubber (≥ 14 mils), nitrile rubber (≥14 mils), neoprene rubber (>14 mils), natural rubber (≥14 mils), polyethylene, polyvinyl chloride (PVC) ≥14 mils, or Viton (>14 mils); and a minimum of a NIOSH-approved elastomeric half mask respirator consisting of protection factor (PF) 10 fitted with organic vapor (OV) cartridges and combination  R or P filters; or a NIOSH-approved gas mask with OV canisters; or a NIOSH-approved powered air purifying respirator with OV cartridges and combination HE filters. 
  
  
• This product is toxic to mammals, birds, fish, and aquatic invertebrates. 

The U.S. Food and Drug Administration (FDA) has issued an Emergency Use Authorization (EUA) for the emergency use of the unapproved product Negasunt Powder for the prevention and treatment of infestations caused by New World screwworm (Cochliomyia homnivorax) larvae (myiasis) in cattle, swine, goats, sheep, horses, donkeys, domestic hybrid equids, and captive wild, exotic, and zoo mammals. Negasunt Powder is not approved for this use. 

For use by employees of federal, state, local, and federally recognized tribal agencies, and persons working under their authority and at their direction. Also for use by or on the order of a licensed veterinarian in NWS infested zones and adjacent surveillance zones as defined by the U.S. Department of Agriculture (USDA). 

For additional information on the EUA and for complete safety information, please refer to the Negasunt Powder NWS Fact Sheet. 

Limitations of Authorized Use 

It is a violation of federal law to use this drug product other than as directed in the authorized Fact Sheet. 

Treated animals must not be slaughtered for human consumption within 28 days of the last treatment. 

A milk discard time has not been established for this product; do not use in animals producing milk for human consumption. 

A withdrawal period has not been established for this product in pre-ruminating calves; treated calves and calves born to treated cows must not be processed for veal. 

Do not use in horses intended for human consumption. Do not use in domestic indoor pets (e.g., dogs, cats, rodents, rabbits) nor in residences. Do not use in birds. Do not use in free-ranging wildlife. 

To avoid overexposure, each individual person cannot treat more than 3 large wounds (>2 inches diameter) a day or more than 30 small superficial wounds (≤2 inches diameter) a day (or an equivalent thereof) with Negasunt Powder or any other coumaphos-containing products. 

Negasunt Powder is authorized for this use only for the duration of the declaration that circumstances exist justifying the authorization of the emergency use of Negasunt Powder 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 declaration is terminated or the authorization is revoked sooner. 

Federal law prohibits the extra-label use of this drug. 

Additional Important Safety Information 
Not for use in humans. Keep out of reach of children. Only handlers wearing required PPE may be in the area during application. Do not apply in a confined, non-ventilated area; provide thorough ventilation. Call a poison control center or doctor immediately for treatment advice if Negusant Powder is swallowed, inhaled, on skin or clothing, or in eyes. Sulfonamides are contraindicated in animals that are hypersensitive to them and in animals with severe renal or hepatic impairment. For external use only on animals. Do not contaminate water, feed, troughs, feed handling equipment, or milk or meat handling equipment. Use with caution in very young, weak, or debilitated animals. In the case of overdose, treat with atropine sulfate or pralidoxine chloride (2-PAM) as soon as possible. The most common adverse reactions associated with organophosphate and carbamate toxicity in animals include frequent urination and defecation, muscle twitching, and watering eyes. 

Important Information about Tanidil 
Tanidil™ is an unregistered product for distribution and use only under a Section 18 emergency exemption. The Section 18 labeling must be in the possession of the user at the time of pesticide application. This product may only be used to prevent or control New World screwworm in and on animal wounds on labeled animal host species. 

For use only by federal, state, local, and federally recognized tribal agencies, and persons working under their supervision; personnel at quarantine stations and areas; veterinarians; veterinarians or certified applicators at livestock and game facilities, zoos, wildlife facilities, animal rehabilitation centers; and wildlife professionals. 

Read the entire label. This product must be used strictly in accordance with this label's precautionary statements and use directions, as well as with all applicable state and federal laws and regulations. Please visit the Tanidil fact sheet for more information. 

Use Period: This exemption is effective on April 27, 2026 and expires on April 27, 2029. No applications of Tanidil may be made under the emergency exemption before its effective date or after its expiration date. 

Credelio, Credelio Quattro, Negasunt, Tanidil, Catron, Elanco and the diagonal bar logo are trademarks of Elanco or its affiliates. © 2026 Elanco or its affiliates 

Investor Contact: Tiffany Kanaga (765) 740-0314 [email protected]
Media Contact: Colleen Parr Dekker (317) 989-7011 [email protected]
Media Contact: Mika Takahashi (765) 335-4070 [email protected]
Media Contact: Season Solorio (765) 316-0233 [email protected]  

SOURCE Elanco Animal Health

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