
my dogs are all on pedigree nugurts (except the oldies who are on nutro senior) and i would change tem off it but i have a friend who feeds royal cannin and her dogs love it and have done really well on it. so changing is up to you.
as for over feeding, aslong as you follow recormendations then there will be no problem, if they seem to be putting on weight then just give them a little less and vica versa.