The FDA has recently published an animal drug safety communication about potential adverse effects associated with an ingredient (isoxazoline) that is in Bravecto, Credelio, Nexgard, and Simparica.
The focus of the communication was regarding the occurrence of neurological adverse reactions such as muscle tremors, ataxia, and seizures in some dogs. The FDA is asking all manufacturers to communicate these risks more clearly on their packaging and labels to both consumers and veterinarians.
Our recommendation has been, and will remain the following:
- If your pet has a history of seizures, DO NOT use these products for flea and tick prevention. Consider a topical or collar option and carefully read all labels on packaging.
- This FDA safety communication does not provide any new information or findings
- The top 3 adverse events that have been observed in pets using these products are vomiting, diarrhea, and lethargy but the occurrence is extremely low
- Since we have begun recommending oral flea and tick prevention in 2015, we have not had any reports of neurological side effects among our canine patients.