Orally Administered BRAVECTO® (Fluralaner) 12-Week Chew Eliminated 100 Percent of Brown Dog Ticks from Infested Kennels Housing Treated Dogs in Recently Published Study

BRAVECTO eliminated kennel infestations of brown dog ticks (Rhipicephalus sanguineus sensu lato)

External imidacloprid/flumethrin collar treatments failed to eliminate all ticks from kennels

RAHWAY, N.J., March 15, 2024 – MSD Animal Health, a division of Merck & Co., Inc., Rahway, N.J., USA (NYSE:MRK), today announced the publication of a recent study demonstrating the efficacy of BRAVECTO® (fluralaner) as compared to external imidacloprid/flumethrin collar treatments. In the study,brown dog ticks (Rhipicephalus sanguineus sensu lato) were eliminated in all kennels housing dogs treated with BRAVECTO. At no time were the kennels housing dogs treated with external imidacloprid/flumethrin collars tick-free, and near the end of the study tick counts in those kennels began to climb.

The study, “Efficacy of either orally administered fluralaner or topically administered imidacloprid/flumethrin for controlling Rhipicephalus sanguineus sensu lato premises infestations” is available at Parasites & Vectors.

“It’s important to kill ticks as effectively as possible given that the longer a tick is able to feed uninterrupted, the greater the risk of a dog being infected with a tick-borne pathogen,” said Jason Drake, DVM, DACVM-Parasitology, director, scientific marketing affairs – parasiticides, global companion animal business unit, MSD Animal Health. “This research allows veterinarians to make informed decisions when recommending tick control practices. In addition, it helps pet owners understand the importance of choosing a product that provides complete and long-lasting protection against newly acquired ticks.”

In the study, 32 dogs were divided into three groups, one group with dogs receiving oral fluralaner (25–56 mg/kg), one group with dogs wearing flumethrin/imidacloprid impregnated collars, and a control group receiving no treatment. Treatments were administered once on day 0. Starting 12 weeks prior to treatment, Rhipicephalus sanguineus sensu lato infestations were established in kennels holding dogs, by placing ticks in the kennels every 2 weeks from day -84 through day -14

Key Findings:

  • A single BRAVECTO treatment reduced tick counts in the infested kennels housing treated dogs to zero (100% reduction) by day 70, and these kennels remained tick free through study completion (day 84).
  • Imidacloprid/flumethrin collar treatment reduced tick counts in kennels by 90% on day 63, but kennel tick counts began to climb after this time point, resulting in a final reduction of 75% at the end of the study.
  • Engorged (blood fed) ticks continued to be found in kennels housing imidacloprid/flumethrin collar treated dogs throughout the study period.
  • Systemic fluralaner treatment was significantly (P = 0.003) more effective at reducing engorged adult female tick counts than imidacloprid/flumethrin collars

The Rhipicephalus sanguineus sensu latospecies, sometimes referred to as the brown dog tick, causes significant concern in certain regions of the world as the vector of disease-causing pathogens, such as Ehrlichia canis (causing canine ehrlichiosis), Anaplasma platys (causing infectious cyclic thrombocytopenia), and various species of Babesia (which can cause babesiosis).i

Previous studies have shown that treatments that protect for a longer period can contribute to improved adherence to treatment recommendations. Long-term treatment not only helps ensure adequate protection against the various flea and tick species throughout the world but also simplifies the process for both pet owners and veterinarians.

To learn more about BRAVECTO and for safety information, visit: https://www.ema.europa.eu/en/medicines/veterinary/EPAR/bravecto.

About BRAVECTO® (fluralaner)

Since its introduction in 2014, BRAVECTO has provided longer-lasting flea and tick protection, with more than 300 million doses distributed in more than 100 countries. BRAVECTO is available in a variety of formulations, including products for both dogs and cats.

Providing pets with continuous flea and tick protection is essential – whether the pet goes outside or not. Contrary to popular belief among pet parents, fleas and ticks are not only active in the spring and summer months, but they are a year-round risk.

Fleas and ticks can easily infest dogs and cats. Ticks can spread serious diseases including rickettsiosis, anaplasmosis and borreliosis (Lyme disease), while fleas are the most common external parasite found on pets and can transmit bartonellosis (Cat Scratch disease) and tapeworms.

About MSD Animal Health

At MSD, known as Merck & Co., Inc., Rahway, N.J., USA in the United States and Canada, we are unified around our purpose: We use the power of leading-edge science to save and improve lives around the world. For more than a century, we’ve been at the forefront of research, bringing forward medicines, vaccines and innovative health solutions for the world’s most challenging diseases. MSD Animal Health, a division of Merck & Co., Inc., Rahway, N.J., USA, is the global animal health business of MSD. Through its commitment to The Science of Healthier Animals®,MSD Animal Health offers veterinarians, farmers, producers, pet owners and governments one of the widest ranges of veterinary pharmaceuticals, vaccines and health management solutions and services as well as an extensive suite of connected technology that includes identification, traceability and monitoring products. MSD Animal Health is dedicated to preserving and improving the health, well-being and performance of animals and the people who care for them. It invests extensively in dynamic and comprehensive R&D resources and a modern, global supply chain. MSD Animal Health is present in more than 50 countries, while its products are available in some 150 markets. For more information, visit www.msd-animal-health.com and connect with us on LinkedIn and X (formerly Twitter).

Forward-Looking Statement of Merck & Co., Inc., Rahway, N.J., USA

This news release of Merck & Co., Inc., Rahway, N.J., USA (the “company”) includes “forward-looking statements” within the meaning of the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995. These statements are based upon the current beliefs and expectations of the company’s management and are subject to significant risks and uncertainties. There can be no guarantees with respect to pipeline candidates that the candidates will receive the necessary regulatory approvals or that they will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.

Risks and uncertainties include but are not limited to, general industry conditions and competition; general economic factors, including interest rate and currency exchange rate fluctuations; the impact of pharmaceutical industry regulation and health care legislation in the United States and internationally; global trends toward health care cost containment; technological advances, new products and patents attained by competitors; challenges inherent in new product development, including obtaining regulatory approval; the company’s ability to accurately predict future market conditions; manufacturing difficulties or delays; financial instability of international economies and sovereign risk; dependence on the effectiveness of the company’s patents and other protections for innovative products; and the exposure to litigation, including patent litigation, and/or regulatory actions.

The company undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise. Additional factors that could cause results to differ materially from those described in the forward-looking statements can be found in the company’s Annual Report on Form 10-K for the year ended December 31, 2023 and the company’s other filings with the Securities and Exchange Commission (SEC) available at the SEC’s Internet site (www.sec.gov).


i Dantas-Torres, F. (2010). Biology and ecology of the brown dog tick, Rhipicephalus sanguineus. Parasites & Vectors, 3(1), 26.