Mobility and Space

My six-month-old is just starting to become mobile. For several weeks now he has been using his arms to move around his blanket in a (usually) counter-clockwise direction and occasionally pulling himself forward one scooch. Now he has begun stringing several forward scooches together so that I turn around and he is already a foot off of his blanket. I don't know how this is going to affect our dog, who is already feeling cramped by our current living situation. My son is extremely fascinated with both pets and tries to reach out and touch them whenever he gets a chance. After having their fur pulled or their ears pinched a couple of times, both pets try to keep their distance. Once he really starts crawling though, that will be a lot harder. The cat, at least, can escape by jumping up onto the furniture, but there is no where for the dog to go other than outside (where it is freezing cold).