The agency said muscle tremors, ataxia and seizures were seen consistently among reported side effects.
The FDA stressed the products remain safe and effective for the majority of animals.
"These products are effective at killing fleas and ticks, but they come with a price,” Marietta veterinarian Dr. Michael Good said.
Bravecto's maker, Merck
said in a statement that the company remains confident in Bravecto because of extensive testing on the product.
"After three years of post-marketing 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, which is defined by international regulatory authorities as less than 1/10,000," Merck officials said.