31/05/2026
Scientists have uncovered a potential explanation for why some dogs experience seizures and other neurological issues after taking common flea and tick medications like Bravecto, NexGard, Credelio, Simparica, and Revolution. Real-world reports show that certain dogs, especially puppies, older dogs, or those with genetic vulnerabilities, can develop tremors, seizures, or other nervous system problems. The study suggests that these drugs may reach the brain through a “back door” pathway called centripetal (retrograde) axonal transport, bypassing the usual protective blood brain barrier. Additionally, certain chemical additives in the medications, such as PFAS compounds, may increase this risk by helping the drugs enter nerve cells or acting as neurotoxic agents themselves. Overall, this research highlights a previously underappreciated nerve pathway that could explain why some dogs are more susceptible to neurological side effects from flea and tick treatments.
