We have one with a fish allergy here. Every time she eats fish she has huge stools and accidents in the house. She is 16 months old. It took me ages to figure that one out!
If they don't find anything medically wrong,(and even if they do) my suggestion would be to go back to square one with potty training and start from there. Lots of times "puppies" regress for one reason or another and need to be reprogrammed. It could be as simple as he tanked up on water and nobody noticed and if everyone went off to work, he was stuck having to go in his crate. And we all know that once they get comfortable going in their crate, tough to break that habit.
It might be that they will need to hire someone to come in during the day for a while or that someone needs to come home at lunch.
Hope their situation improves.
Merry Christmas, all!!
