I'm not certain that the kidney failure is causing the incontinence. You might wish to have you vet check for a bladder infection.
Kidney failure is pretty much inevitable with old cats. If I'm not mistaken, these cats tend to produce less urine, not more, as the kidneys become less efficient at removing the badness from the blood. The treatment is to increase fluids, building blood pressure and forcing the kidneys to work harder. This increased blood pressure is not good for the cat as it will lead to really ugly things like blindness and seizures.
Suffice it to say that the end result of owning an old cat is no fun.
Kidney failure is pretty much inevitable with old cats. If I'm not mistaken, these cats tend to produce less urine, not more, as the kidneys become less efficient at removing the badness from the blood. The treatment is to increase fluids, building blood pressure and forcing the kidneys to work harder. This increased blood pressure is not good for the cat as it will lead to really ugly things like blindness and seizures.
Suffice it to say that the end result of owning an old cat is no fun.