Very housebroken and can be in the house for 8 hours or more without an accident all of a sudden at night when we sleep she decides she is going to urinate on the couch or spare bed. We put plastic on there and have an old comforter and wash it everyday but she does it every night now. Even though she is left out everynight once or twice.
It can be a bad habit, but in case your dog is spayed, in some small percent of patients can cause incontinece. Unfortunately for this you must contact your vet for treatment. Can be inflammation of the bowel, but for further analysis you should contact your vet. Make urine analysis.