Re: Recent FDA Warning About Certain Flea and Tick Products– NO increased cause for concern

​On September 20, 2018, the Food and Drug Administration (FDA) in the USA released a warning to veterinarians and pet owners regarding the use of the isoxazoline class of flea and tick products.  A small percentage of dogs on such products have experienced negative side effects, some of which have included neurological signs such as tremors and seizures.
Link to the FDA announcement can be found at FDA bulletin re flea and tick products
Two of the products in the isoxazoline class, Bravecto® (Merck Animal Health) and NexGard® (Boehringer-Ingelheim/Merial) are commonly recommended by our veterinarians.
We have been in contact with both companies and wish to share with you their responses to the FDA warning.
Important notes:
·         The FDA considers products in the isoxazoline class to be safe and effective for dogs and cats but is providing this information so that pet owners and veterinarians can take it into consideration when choosing flea and tick products for their pets.

• Health Canada and the Canadian Food Inspection Agency have not issued any warnings, and reports of adverse events remain very rare and stable (less than 1 in 10,000 doses). No new concerns are present.
• A few of the dogs participating in the clinical trials for both products did show some side effects including mild gastrointestinal upset, itchy skin, tremors, or seizures. The frequency of these negative side effects was considered “very rare”. Both product inserts recommend that caution be used if prescribing to dogs prone to seizures, or to consider alternative products instead for these patients.  This information is not new since the products arrived on the market several years ago.
• It is important to understand that this class of drug does not cause neurological signs such as seizures, but rather may initiate such signs in seizure-prone dogs.
• Since becoming available, NexGard® has been used in more than 100 countries and more than 200 million doses have been sold worldwide.  Bravecto® has been used in more than 85 countries and more than 80 million doses have been sold. 

We also want to reassure you that for the vast majority of dogs, these products remain completely safe and are effective against fleas and ticks and in preventing the diseases they can transmit.  We will continue to recommend them, and unless your dog is experiencing negative side effects, we advise you continue using NexGard® or Bravecto® as prescribed.
 
Statement from Boehringer-Ingelheim/Merial [NexGard®]:
 
“You may have seen some information recently about a safety communication that was issued by the Food and Drug Administration in the United States about oral flea and tick products in the isoxazoline class. This class includes NexGard® and several other products, and we wanted to provide our pet parents with some additional information.
The FDA considers products in the isoxazoline class to be safe and effective for dogs and cats and issued its safety communication so that pet owners and veterinarians can take it into consideration when choosing flea and tick products for their pets.
We are confident in NexGard®. It is a trusted treatment for the control of fleas and ticks in dogs and continues to be safe and effective. There is potential risk with all medications, and with NexGard® the benefits of flea and tick control vastly outweigh the very low risk of an adverse reaction. The reported signs are rare with NexGard® – less than one case in every 10,000 doses.
The well-being of our patients is incredibly important to us and we take great care in completing a proper examination and assessment to determine the most suitable course of treatment. We also do research into the products that we prescribe in our clinic so we can have complete confidence in the treatments being recommended.”
 
Statement from Merck Animal Health [Bravecto®]:
“Merck Animal Health, the manufacturer of the Bravecto portfolio of products, remains confident in the safety and efficacy of Bravecto, which has been established through comprehensive clinical research in more than 170 studies. Nothing has changed about the Bravecto product.
 
The current FDA communication is based on information gathered on the isoxazoline class as a whole and therefore applies to all products in the class, which includes Bravecto.
 

• After over three years of surveillance of more than 80 million Bravecto doses distributed in 85 countries, the overall worldwide reporting rate for neurological signs, including seizures, remains classified as very rare.  Very rare is defined by international regulatory authorities as less than 1 in 10,000 incidences.

 
Every molecule is unique, even within a class, and each has its own safety profile. This is why it’s important for all pet owners to speak to their veterinarian before making a decision about flea and tick control products for their dog.
 
Nothing is more important to Merck Animal Health than the safety and efficacy of our products and the well-being of animals. We encourage all pet owners to speak to their veterinarian before making a decision about flea and tick control products. More than just a nuisance, fleas and ticks transmit disease and pose animal and human health risks. It is critical to protect pets from these parasites.”
 
Please rest assured that our team continues to recommend all products based on clinical safety and efficacy, and our veterinarians take your pet’s individual needs into consideration when recommending any treatment plan.  If you have concerns or questions, do not hesitate to call our hospital.
 
 
 
Sincerely,
 
The Team at Centennial Animal Hospital and Gravenhurst Veterinary Services