WASHINGTON (CBS) – The FDA is warning pet owners that some flea and tick drugs have been associated with seizures in dogs and cats.

The agency’s alert concerns drugs in the isoxazoline class, which includes FDA-approved medications Bravecto, Credelio, Nexgard and Simparica.

READ MORE: Service Resumes On Green Line Hours After Crash, Operator On Leave

“Isoxazoline products have been associated with neurologic adverse reactions, including muscle tremors, ataxia, and seizures in some dogs and cats,” the FDA says. “Although most dogs and cats haven’t had neurologic adverse reactions, seizures may occur in animals without a prior history.”

The FDA says these drugs are considered safe and effective for dogs and cats, but pet owners should talk to their veterinarians to determine which tick and flea medications are appropriate.

MORE NEWS: Newbury Street To Have 3 Car-Free Days In August

Pet owners should contact a vet if their dog or cat has an adverse reaction to isoxazoline products.