Hello, I read your comment about your Shih- Tzu puppy. Have you actually had your dog to a vet and been told he has kidney problems? The reason I asked, I raise Shih-Tzu puppies and it is there nature to take about 1 year to potty train. As you said they don't make poo-poo accidents as often but up to a year the pee-pee mistakes are here and there. More with males than females. A good way to potty train is to take your puppy outside about 10 minutes after he wakes up, and 15 minutes after he eats. That usually works very well.You will have to clean your carpet very well or you will have an on going problem. Remember males are a little harder to train, but he will get there. They are the best dogs you could ever own. I currently have 4, I love all of them. I don't believe I will ever have any other breed. Good luck with your puppy.
Dealing with kidney issues is a really difficult proposition. The dog doesn't usually know he's about to urinate, so they're just a walking accident waiting to happen. One thing that helped our dog while going through kidney failure, was using CranAssure. It helps sweep crytals and debris out of the urinary tract and makes the dog a lot more comfortable. Our dog's accidents were greatly reduced once we started her on the CranAssure. It also has lots of good vitamins in it that are good for overall health.
It sounds like he's got his scent so thoroughly attached to your dining room that he now thinks it's OK to pee there when he isn't in accident mode. You'll need to have that area professionally cleaned to get as much of the urine odor out of there as possible. Think of it as starting with a clean slate, and religiously keep up with deodorizing any future accidents.
What does your vet say about this condition as far as treatment goes? How did his kidney lab work turn out? Once our dog was in severe renal failure, giving her calcium in the form of Tums helped a great deal with the urine accidents as well. The calcium binds to phosphorus and sweeps it out of the body. Phosphorus needs to be avoided as much as possible where kidneys are concerned, but a growing puppy needs it for healthy teeth and bones. Check with your vet on that question.