Urine Marking Inside House :o(

Question
Five days ago, my daughter and son-in-law adopted a shelter puppy, a 10-month-old, just neutered, male Boston Terrier as a playmate for their sweet-natured six-month-old Labrador female, also a shelter puppy, that they've had for four months.

The two puppies hit it off really well at their meet-and-greet at the SPCA, and seem really well-matched.  The Lab gladly shares everything with the new little guy, and he is a delight, except for one thing.  He lifts his leg and marks inside the house!  He was described as "not housebroken," and is learning well not to have accidents in the house, but the marking is the real problem.

Mr. Pickle is a great puppy in every other way, and we would be grateful for any thoughts or advice.

Thank you so much.

Answer
It is possible the problem will slowly go away itself as he becomes more comfortable in the house, no other males over mark him, and the hormones left in his system dissipate.  I would add a good obedience program for both.  
Having a good pack structure reduces such problems.  The dogs see all the
people and dogs in the household as a pack with each having their own rank in
the pack and a top dog.  Life is much easier if the 2 legged pack members
outrank the 4 legged ones.  You can learn to play the role of top dog by
reading some books or going to a good obedience class. A good obedience class
or book is about you being top dog, not about rewarding standard commands with
a treat. Start at http://www.dogsbestfriend.com/

If you are going to have 2 dogs, a neutered male and spayed female are the best combination.  They settle in as the top male and female dogs, hopefully below the people in status.  If you don't have a Spot Buster, you might pick one up.  Many people that don't even have pets have one.  If she is not spayed yet, most vets like to do it at 6 months.  Put it off, and you may have to go through her being in season.  That could undo all the work on eliminating the marking.  

Catching him in the act of marking calls for stronger corrections than the
otherwise effective "Bad dog!".  When it misbehaves, throw it on its back, and
growl "Bad dog!" right in its face.  Hold it down until it lifts one back leg
to show submission.   You can pick him up with your hands behind his front
shoulders and hold him up with his back to you.  Keeping him far enough away
to keep his head from smashing into your face, hold him until he stops
struggling and relaxes.   Others like the squirt bottle.  Fill it with water
and a little vinegar or lemon juice.  Give it a squirt in the face as soon as
it misbehaves.  Dogs hate that.  

You may need to crate him when you aren't around.  Your house and dog
will be much safer with the dog in a crate when you are away.  The dog may be
happier in its den than loose in the house.  It relaxes, it feels safe in its
den.  It rests, the body slows down reducing the need for water and relieving
its self.  Dogs that have been crated all along do very well.  Many of them
will rest in their crates even when the door is open.  I think the plastic
ones give the dog more of a safe, enclosed den feeling.  They are harder for
dogs to open too.  Metal ones can be put in a corner or covered with
something the dog can't pull in and chew.  Select a crate just big enough for the full grown dog to stretch out in.

Leave it some toys.  Perhaps a Kong filled with peanut butter.  Don't leave
anything in the crate the dog might chew up.  It will do fine without even any
bedding.  You will come home to a safe dog and a house you can enjoy.

Accidents and damaged possessions are the fault of whoever was watching the puppy.  When you are watching it, immediately correct it as soon as it goes for anything except its own toys.  In a quiet, but firm voice ''Bad dog, its name drop!''.  Gently remove what ever and replace it with one of her toys, or if older, hold eye contact until the puppy drops it.


A dog that has not been crated since it was little, make take some work.
Start out just putting its toys and treats in the crate.  Praise it for going
in.  If you have been able to trust it with any bedding, put that in the crate.
Feed it in the crate.  This is also an easy way to maintain order at feeding
time for more than one dog.