This is a long shot, but Alabama is a neighboring state. All reports I can find do indicate it is a child's foot, but do not give any indication of the age of the child. I thought I would post it here. Peace and loving thoughts go out to this little one, whomever they are.
http://www.cnn.com/2008/CRIME/09/22/dog.foot.ap/index.html
http://www.cnn.com/2008/CRIME/09/22/dog.foot.ap/index.html