I've tried the Avantix II this year and it has been worthless. All efforts have been worthless...it's kept them down to a dull roar but the dog is still scratching. Never saw a year for fleas like last year and this one.....before I could always get by with a flea collar but not now.
Good luck and let me know if you find anything besides the usual...I've tried the healthy route(my usual) and the chemical route(collars, shampoo, dusting, meds on the skin/back, Ivermectin, etc.) but these are some kind of super fleas!