I think it could be the bladder control thing and drinking large amounts of water. If he drink lots it would be best for you to let him out not long after so he can relieve himself. We have a 15 y/o jack russell and he just couldn't hold him bladder anymore. It got to the point where he would 'tell' you he wanted to go out but he'd get to the door and just wee. In the end he couldn't hold on for poos, so he & the other pooch are now outside dogs as every morning I was cleaning up dog urine.... We also moved house, so perfect timing for us to make them live outside permanently.