Interceptor (milbemycin oxime) is either back on the market or coming back soon... http://news.vin.com/VINNews.aspx?articleId=35393
I could get you some Sentinel and send it to you if you can't source it there
Thats great for americans but Virbac aquired sentinel and sentinel spectrum not the same company that bought out that portion of novartis. So americans might get interceptor but Canada is SOL.
Interceptor will not be coming back within any forseeable future....