The flea and tick pills Bravecto, Nexgard, Simparica, and Credelio have been flagged by the FDA as potentially dangerous to pets. After approving these products, the administration received reports that the medications were triggering muscle tremors, loss of balance, seizures, and other neurological side effects in both cats and dogs. Epileptic animals may be especially vulnerable, but even pets without a history of seizures have experienced these symptoms.
The drugs are still safe and effective for most pets, according to the FDA, and there are no current plans to take them off the market. Instead, the administration is asking manufacturers to update the labels to reflect the possible side effects. In the meantime, pet parents giving their animals the pills should contact their vet if their cat or dog has a preexisting neurological condition or if their pets start exhibiting any of the symptoms mentioned above.
If the drugs aren't causing any issues, the benefits of keeping your pet on flea and tick treatments will likely outweigh the risks. Even when these external parasites don't carry harmful pathogens like the one that leads to Lyme disease, they can cause severe blood loss in affected animals.