Dog Marking Codes and Dog Territory Marking - Two Males at Home

Dog territory marking, dog scent mixing, male spraying, dog marking - it does not matter what you call such bad dog behavior. It may be dog instinctive behavior, but no one wants a dog relieving itself in the house!
Let's say you have an aging male dog who, up until now, has been somewhat of a model citizen. You want you new puppy to learn from him so that training will be easier, and the pup will grow up with some social skills.
You bring the new pup home. The old dog tolerates him, but he clearly is not thrilled to have another male in his house. In a situation such as this, we humans feel a bit guilty, and we want to give the old timer extra affection to be sure he does not feel left out.
Instead of reacting emotionally, the best thing to do, in reality, is to allow the dogs to acclimate to one another. Correct the old dog if he is too rough on the newcomer, but surely correct the pup if he is out of line. Balance is the only thing that will bring harmony between two males (actually, any dogs being together need this balance).
Favoring the dog you had first can easily lead to dog aggression, dog possessive behavior, dog humping and dog mounting behavior, and of course, the dreaded territory marking.
If one of your dogs or both is making his own version of dog marking codes, then do this.
Every day, walk the two dogs together on a heel for a minimum of forty-five minutes. During this time, they are focused on you, their Pack Leader, and they are learning to co-exist with one another. If one dog is a high energy type, also run him in the evening to keep him near the level of the other dog.
Now, if your old fellow is just too old for real walks, then do a couple of psychologically challenging exercises with him and the pup. (Actually, these should be done whether or not the older dog is still young enough to walk.) Make the pup and old dog sit or lie down beside each other for five minutes, then ten, then fifteen, and build it up slowly. What you are doing in this exercise is something that a pack leader in the wild would do. The Alpha Leader will herd the whole pack together and make them sit or lie down next to each other for a countless amount of time. This teaches them to work with one another and to respect each other.
It is important to be able to pet any dog you wish without any of the dogs complaining about it. Is it favoritism to pet one dog and not the other? Certainly not. I will often pet my Border Collie and tell another approaching dog, "Not now." I have a right to spend personal time with any dog that I wish. When you try to pet both dogs at the same time, they start competing with each other for your affection, instead of learning to respect your preference to have personal time with each one of them.
If the dogs start to fight over something - anything! - then "claim it" back. To claim food or any other object, make eye contact with the dog who has what you want. Straighten your shoulders and lift your head with confidence. Step between the object and the dog with your feet spread half way between a military "Atten-hut!" and "At ease." Hold your ground, eye contact, and posture until the dog lies down and turns away. This means the dog has surrendered the object.
Turning the old dog and pup into a "pack" and making them work together is the sure way to stop their individual bad dog behavior of spreading their dog marking codes and make them into a team, so you can restore peace and proper fragrance to your home! ( by Rena Murray )