Leg lifting is both behavioral and instinctual. Marking will get started as a doggy way or declaring territory (both males and females do it, but intact males with those hormones are the worst), often after another dog has marked a spot. Having said that, a dog that is not permitted to do so will not. It is a housebreaking issue when they mark in the house. I know of plenty of breeders with stud dogs who do not mark in the house ever. I've had plenty of intact males in the house including a Maltese. I never let them start the behavior so we had no problems. If you aren't actively house training your dogs and you have 15, of course they'll urinate all over the place. It is a dog thing, not a toy breed thing. I think most large breed people simply don't tolerate it.