Haven't used Frontline but my Gypsy Rose absolutley freaks out when I put ANY flea stuff on her.. she goes crazy... I now tend to do it just immediately prior to a walk so her attention is taken away from it.... no vomiting though ever.. She is really upset by it though and I've never had a dog act like this. When we go to Spain in Dec and come back into UK it will be Frontline that they use so we'll see but my little one, Gizzie doesn't react like Gypsy!!
