He may still get to the point where he won't need the mat, papasierra. Many dogs go through an 'angst' phase from about 6 - 9 months, where they get anxious about things that have not bothered them in the past and may not bother them in the future. Let it go a few weeks, then try removing the mat again. You may find that he's gotten over that particular phase of development and won't need the rug anymore.
In the meanwhile, I don't suppose you have a few pics of your boy to share with us, do you?
