Would it be silly of me to enquire as to whether or not you have taken your dog to the vet to be checked for a possible kidney infection, cystitis, or some other such health issue? Have there been any changes in your dog's enrionment? A new baby, another addition to the household of the fourfooted kind, a separation, divorce, some sort of statis amongst the family, a change in routine such as a new job? Pets are extremely sensitive to human vibes and if this problem is not health related, or environmentally produced, could it be possible that your dog might be experiencing another stressor outside of your control? Just asking.