This is interesting as I have been wondering about this recently. Our girls are fine on Advantix (not Advantage) but I am going to have to change over to Frontline. May sound strange but both girls will shortly have their Pet Passport (Europe) and prior to entry back into UK we have to contact a vet in France or wherever to administer Frontline. It cuts the costs to buy it and take it with you to give to the vet LOL so I will probably be changing before we go to Spain later in the year! Ana xx
