NexGard (afoxolaner), a flea and tick treatment developed by Merial, now part of Borhringer Ingelheim, had previously been approved for the treatment of flea and tick infestations, it had not been approved to prevent Lyme disease often associated with ticks. However, following the release of results of two studies on the effectiveness of NexGard in preventing the transmission of the Borrelia burgdorferi bacteria responsible for causing Lyme disease, the FDA approved the drug for the prevention of Lyme disease.
The mechanism of NexGard’s Lyme disease preventative action occurs through the killing of deer ticks that serve as Borrelia burgdorferi‘s hosts. With no way for the bacteria to be introduced into dogs, there is no way for them to cause the symptoms associated with Lyme disease.
“Both studies measured the transmission of B. burgdorferi to dogs after exposure to infected ticks. All dogs treated with NexGard tested negative for B. burgdorferi infection, demonstrating that transmission was prevented as a direct result of NexGard killing infected ticks. This research shows that NexGard provides a full month of protection against black-legged ticks infected with the bacterium that causes Lyme disease.”
— Zach Mills, Executive Director, US Pet Veterinary Professional Services