We had a really TERRIBLE experience with Advantix. Lexi had a neurologic reaction to the ointment placed on her neck. She started donkey kicking out of no where… it was really scary.
Of course there will be people who don't have any problems with products- and that's great. But if your dog is having problems after having used Advantix-- chances are that IT is the problem. A quick google search for Advantix Side Effects will bring up a list of user complaints.
http://www.google.com/search?hl=en&q…oogle+S earch
And if your dog has similar symptoms to the ones listed, I would definitely recommend stopping the use of the product immediately.