We've tried K9 Advantix three times on our Shih Tzu and had scary side effects. The first time was fine but the second (lethargic for 2 days) and third (panting and restless) resulted in side effects. We actually stopped using it after the second application 6 months ago but applied it again last night after finding a tick on her. She woke me up at 2am and 4am panting. We are going to stop using it and look into trying Frontline Plus. Any thoughts?