change is dogs routine

Question
Hi,  my boston terrier is just about 6 months old.  I have had hime for about 6 weeks and he is about 95% potty trined (he was previously indoor trained and I am getting him outdoor trained).  I have noticed over the last couple fo days that his potty routine has changed in the last couple of days and he has gotten up in the night and pottied in the house (a rare occurance).  Could this just be as he is getting older his system is digesting differently?  He has been on the same food since I got him and up to know he's done well and his day to day routine is pretty routine and not changed.  Am also wondering if, although he is still a puppy at 6 months, maybe puppy food is too "rich" for his system?  anyways, just looking for insight if you might have any.

Thanks

Answer
It may be that you are possibly feeding him a little too much,even as little as a reduction as half a cup less can make a big difference

6 months is about the time to slowly start to change to adult food,and do that by mixing the food together in the bowl,at first just a little bit of the new food,then over time till that is mostly what he is getting

It is also around the age where they might want to challenge you for dominance-and sometimes they do this by soiling in the house because they think they can,and a good way to get on top of this is to take him to obedience classes