News Details

Zoetis Announces FDA Approval of Simparica Trio® (sarolaner, moxidectin, and pyrantel chewable tablets) New Label Indication for Prevention of Borrelia burgdorferi Infections in Dogs

January 4, 2022

Simparica Trio proven to block the pathogen that causes Lyme disease by killing deer ticks

PARSIPPANY, N.J. –January 4, 2022– Zoetis today announced that the U.S. Food and Drug Administration (FDA) has approved a new label indication for Simparica Trio® (sarolaner, moxidectin, and pyrantel chewable tablets) for the prevention of Borrelia burgdorferi infections as a direct result of killing Ixodes scapularis vector ticks (black-legged or deer ticks).  Simparica Trio is approved for dogs eight weeks of age and older weighing 2.8 pounds and greater. Simparica Trio is the first and only combination product demonstrated to prevent infections that may cause Lyme disease by killing deer or black-legged ticks.

“Tick-borne diseases are a serious threat to pets and Lyme disease, caused by Borrelia burgdorferi, is transmitted by deer ticks. It is critical to have easily accessible and effective options for preventing infections available to protect dogs from ticks so they can spend more quality time with their owners,” said Jen Sheehy, DVM BCPA, Medical Lead for Parasitology at Zoetis. “This new efficacy claim provides a new tool to veterinary teams who understand that healthy pets mean happy people and who work every day to provide the best care for our dogs.” 

Lyme disease is one of the most common tick-borne illnesses transmitted to dogs and data shows that it is a growing threat to dogs in the United States.1 This is the first new indication for Simparica Trio since its approval in February 2020, and it is particularly significant as ticks are a threat year-round. In fact, deer ticks that can carry Lyme disease are especially active in cooler months.2 In 2020, one in 20 dogs across the United States tested positive for Lyme infection.3

“Once dogs are infected with Borrelia burgdorferi, the bacteria’s unique mode of motility allows it to rapidly disseminate throughout the body. This can make the infection difficult to treat,” said Dr. Richard T. Marconi, Ph.D. (Microbiology & Immunology, Virginia Commonwealth University Medical Center).i “The most important thing we can do is to prevent infection in the first place using a comprehensive strategy that includes the use of an effective tick preventative product and vaccination.”

Simparica Trio delivers on Zoetis’ commitment to innovation in parasiticides

The evolution of Simparica Trio’s labeling is just the latest example of Zoetis’ commitment to next-generation parasiticide products and solutions for veterinarians, enabling them to provide the best prevention and treatment options for pets. Simparica Trio is the first and only product to provide all-in-one protection against heartworm disease, ticks* and fleas, roundworms and hookworms** in a single monthly chewable. Now with FDA approval for the prevention of Borrelia burgdorferi infections by killing deer ticks, Simparica Trio can deliver the comprehensive protection that every dog deserves.

This recent label expansion also included approval for the treatment and control of immature stages (L4 and immature adult) hookworm, which helps provide a more comprehensive intestinal parasite control program. With this addition, Simparica Trio is now approved for the treatment and control of roundworm (immature adult and adult Toxocara canis and adult Toxascaris leonina) and hookworm (L4 and adult Ancylostoma caninum and adult Uncinaria stenocephala) infections. Treatment and control of immature and adult roundworms and hookworms help reduce environmental contamination from worm eggs and lowers the risk of infection in dogs.


Use with caution in dogs with a history of seizures. Simparica Trio contains sarolaner, a member of the isoxazoline class, which has been associated with neurologic adverse reactions including tremors, ataxia, and seizures in dogs with or without a history of neurologic disorders. The safe use of Simparica Trio has not been evaluated in breeding, pregnant, or lactating dogs. The most frequently reported adverse reactions in clinical trials were vomiting and diarrhea. See full Prescribing Information.

About Lyme Disease

Clinical signs of Lyme disease in dogs include lameness, enlarged lymph nodes, fever, lack of appetite and lethargy. In some cases, it can also lead to kidney failure. It is possible for a dog to be infected with the disease  and not show clinical signs.

About Zoetis

As the world’s leading animal health company, Zoetis is driven by a singular purpose: to nurture our world and humankind by advancing care for animals. After nearly 70 years innovating ways to predict, prevent, detect, and treat animal illness, Zoetis continues to stand by those raising and caring for animals worldwide -- from livestock farmers to veterinarians and pet owners. The company’s leading portfolio and pipeline of medicines, vaccines, diagnostics and technologies make a difference in over 100 countries. A Fortune 500 company, Zoetis generated revenue of $6.7 billion in 2020 with approximately 11,300 employees. For more information, visit

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*Lone Star tick (Amblyomma americanum), Gulf Coast tick (Amblyomma maculatum), American dog tick (Dermacentor variabilis), black-legged or deer tick (Ixodes scapularis), and brown dog tick (Rhipicephalus sanguineus)

**Roundworms (Toxocara canis and Toxascaris leonina) & hookworms (Ancylostoma caninum and Uncinaria stenocephala)

iDr. Richard T. Marconi has a consulting relationship with Zoetis.


  1. Veterinary Practice News. Study shows increase of Lyme disease in dogs. Accessed November 29, 2021.
  2. Companion Animal Parasite Council. Accessed November 29,
  3. CAPC: Parasite Prevalence Maps Canine Lyme Disease USA 2020. Accessed November 29, 2021.
  4. Parna Ghosh, Meriam N. Saleh, Kellee D. Sundstrom, Michelle Ientile, and Susan E. Little. Vector-Borne and Zoonotic Diseases. Jan 2021.11-19.

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