smt, Our greyhound, recently retired, started her 2nd course of Panacur, day 1 of 3, the day before yesterday and responded similarly to yours. Couldn't sleep, compulsive licking (bedding and herself), agitated, looking at the air is if there were bugs flying. It stopped by the next day. Our adoption group recommend we wait a day before continuing day 2 of the 3 day course. Our adoption group said they have never seen this before. It may have been a coincidental allergy to something else but he timing is suspicious.