Our 1 1/2 yo beagle has been housebroke for quite a while and has lived both inside and outside since we've had him. He's been back inside (hopefully on a permanent basis now) for over a week now and other than some separation anxiety issues (that are being successfully worked through, so far) he's been a GREAT inside dog. He doesn't chew up things, stays off the furniture, doesn't make noise, and no potty accidents... until tonight. He didn't "go to the door" to signal he needed to go out or whine or anything obvious. He was in our son's room playing with our boys and suddenly our older son called out that the dog was peeing on the floor and my son's bean bag! ). My husband and I were shocked. We scolded him and made him go lay down and cleaned up the mess. (I saved the bean bag, btw!!)
What would cause an otherwise housetrained dog to just do this? Now I've lost confidence in his potty habits and find myself paranoid it'll happen again. Any ideas?