My girlfriend and I recently adopted a nearly 3 year old Great Pyrenees. Since we are both at our respective homes for the summer (both still in college), he is living with me and my parents and sister for the time being. Despite only being around me for a minimal time though (in the grand scheme of things) he seems to suffer from something similar to separation anxiety when I'm gone. I'll try to fill in background information in the following paragraph.
I have had him since July 6th. He was at that time staying at the previous owners' parents house where he had been for around 2 or 3 weeks. He spent the first night with my girlfriend and I at her parent's house, and had no issues. He then made the 5 hour car ride (with stops of course) to my house where he has been ever since. From the moment we picked him up, he does not stop following me (not a bad thing...just filling in the back story). If I go outside for whatever reason, he typically either waits at the door or watches me through a large window we have in one room of our house. The problem arises when I am gone for any length of time. Typically if I'm gone for anything more than 20 minutes, and he has free reign of the house, I come back to find a mess either upstairs or in our basement.
To my knowledge he has not had any issues when I am around, and only 1 (of several) has been on the main floor of our house. All the rest are typically upstairs or in the basement as I said. Another kicker is that if he is kept in my room while I am gone, he does not have issues...gener ally just lays/sleeps on my bed or at the foot of my bed.
Things that could cause it(?):
He was/is on a diet of Old Roy Lamb and Rice Meal. My girlfriend and I tried to change it to Purina Lamb and Rice, but upon doing this, his stools became more runny and had a green tint. When we were trying to swap him over, we spent about 10-12 days gradually adding more Purina and less Old Roy. I didn't realize his stools were affected until day 7 or so, and didn't attribute it to the food until a few days after that. He has since gone back to all Old Roy. Side question...any thoughts on Old Roy? I've heard arguments both for and against cheaper dog food.
Shots. When we got him we thought he was up to date on all his shots. I called the veterinarian to double check though, and they said that they had not seen him since his shots as a puppy (March of 2006 I believe). This should all be resolved by the upcoming Wednesday.
Food again...My family has another dog, a 8 year old Golden Retriever who eats Purina of one kind or another (not sure which type). While my Great Pyr does not normally go for my family's Golden's food, there are opportunities when he could get into it without anyone knowing.
Any [more] ideas on what could be causing the problem, or do you have anything to recommend to break him of this habit? My girlfriend and I go back to school in a month, and I'm not looking forward to replacing all the carpet in my apartment when I move out next year.
Thanks