Dog Incontinence.
Urinary incontinence in Dogs.

My dog has received a good education concerning hygiene, but he has started to pee at home. Is this a symptom of getting older?
It could be related to his kidneys. Dog Incontinence or Urinary incontinence in older dogs is common. It happens when the dog drinks more, he will produce more urine, and the bladder will need to be vacated frequently. This is why, older dogs pee during the night; while they are clean the rest of the day when there's someone that takes them out for their needs. Keep a close control of the amount of liquid he drinks and inform your veterinarian. Watch if urine comes out of the vulva drop by drop, in case of a female, specially if she does not notices. Give more attention to your dog when he asks to go outside. Try to leave him alone for short periods, taking him out previously for his needs.

Dog Heart Attacks