1. At 12 years, your dog is showing signs of aging. 2.He can't stand or walk by himself which is indicative of perhaps a untreated hip problem. 3.He has no energy, and doesnt even ask for food and confined to a place...might be suffering from depression aswell. 4.Vets have suggested arthritis and maybe a kidney problem.5.Increased urination and water consumption are all serious indicators of a sick dog. 6.He has no bladder control or is too weak to even urinate out or in the bathroom.
These are multiple complications.Imagine a human facing the same issues, would you say it is a serious problem then or not!?! WHAT ELSE NEEDS TO HAPPEN TO THE POOR GUY FOR YOU TO REALIZE THAT IT IS A SERIOUS PROBLEM, WHICH CAN ONLY BE SOLVED BY A GOOD VET AFTER EXTENSIVE TESTS AND MEDICATION AND NOT ON FORUMS LIKE THIS BY UNQUALIFIED PEOPLE INCLUDING ME. Take some time, effort and money if you care for him.