Bullmastiff urinating when left alone

Question
Hello! We have a wonderful 3 year old male bullmastiff. He has a great temperament, He loves his crate, and is housebroken. When we go out (either for an hour or off to work) he is in his crate.  We have tried to leave him out, even during short  trips to the corner store, but when we return, we find that he has urinated in one of 2 places in the house (the same spot in our family room, or the same spot in our dining room). The location of his crate is going to be used for a nursery, and we were hoping to break him of needing it while we aren't home.  We thought he might suffer from separation anxiety, but he is not destructive while we are away (other than peeing in the house).  Any suggestions on how we can break him of this, or wein him off the dependency on the crate while we are away?    Thanks so much!

Answer
Separation anxiety demonstrates in many ways and a male "marking" the home might be one of them.  Dogs "scent" to call the "pack" back!  I suggest you confine the dog to an area where his marking behavior is not an issue, such as the kitchen, and not allow him run of the house when you are not at home.  Marking can also be a signal from a dog (and the Bull Mastiff is a breed that's intended for serious business) to guard or warn off potential invaders, so your dog might actually be attempting to secure your home when you are gone.  You might want to establish some psychological rank over this dog by making him earn everything for quite a while; using positive reinforcement, teach him a simple obedience trick (such as "sit" but don't use that word).  I suggest you go to karen pryor's website and learn about positive reinforcement/clicker work and use that.  Make the dog earn his food, his interaction with you, his going out and coming in, for a few weeks.  This will put him in his psychological "place" and relieve him of any idea he might have that he's "in charge" when you're not at home.  When a dog has free run of the house, and that dog is of a breed which is designed to protect and defend, that's a lot of responsibility!  Relieve him of the necessity for his guarding/protecting your property.  And since you mentioned a nursery, I certainly HOPE you have heavily socialized this dog to babies and young children!