How can I ensure I get to keep my dog in the process of getting kicked out of my parents?

Many 18 year older people have family issues and do not like their parents. In most cases, things get better. Perhaps you or your family need family counseling. As far as the dog goes, as long as your parents care for him, he may be better off with them than with you living on the road, or moving from friend's apartment to friend's apartment. However, I don't know all the facts. Perhaps you are a really mature 18 year old with a good paying job who can support yourself and a dog comfortably. Legally, in PA, dogs are like personal property, whoever can prove they paid for him or her, owns him.