I am sorry to hear you are worried about Scrappy. Your main concerns are that he is not playing, and that he had an accident in the house? Was it a BM accident, or urine?
My name is Rebecca. I am a veterinarian and will do my best to help.
I would not limit water, until we find out why he had an accident. He might have a physical problem such as a bladder infection, or even something like diabetes that makes him need to drink more water, and then because he drinks more, he has an accident. He may need the extra water if he has a bladder infection or other problem.
If he were mine, I would do a urinalysis at your veterinarian to be sure there is no infection, no glucose in his urine, and that his urine appears normal before I limit his water. If he has a bladder infection, or finding and treating any physical problem he has, should stop the accidents and get him back to his normal playful self.
If the urinalysis is totally normal, then I might consider blood tests next. Only if a physical exam, urinalysis and blood tests are all normal would I consider limiting his water intake.
By not being playful with his toys, he is telling us something is wrong, and we should listen. I would start with a urinalysis if he were my own dog. Please let me know what else I can answer or help with, and how he is doing. Kindly consider rating my answer so the website knows to credit me for helping you. Please do let me know how else I can be of help. Rebecca