My dogs night time behavior has changed? Need input of causes and solutions.

I have a 7 year old German Shepard. Recently, when I work late (two nights a week until 3am) he will need to go to the bathroom anywhere from 4-6am. This happens even when he is let out as late as 11:30pm to go to the bathroom. Every other night, he is let out at 11pm and then has no problem being let out at 8am or even later. A couple of times, he has even went in the house. What could be the cause of this change? He does not have diarrhea. *NOTE: I have had this routine since August, but only within the past month has it been an issue. And only on the nights I work late.*

Asked by Member 842876 on Jan 23rd 2013 in House Soiling