1 Multiple sclerosis (MS) is a disease that causes demyelination (disruption of the myelin that insulates and protects nerve cells) of spinal nerve and brain cells.  Although the exact case is unknown, multiple sclerosis is considered to be an autoimmune disease.
The skunk is not a rodent. They belong to the family Mephitidae and the order Carnivora which does not include rodentia. They are sometimes placed in the family Mustelidae (weasels) but have been discovered to be less related than was thought.
The groundhog (Marmota monax), also known as a woodchuck, or whistlepig, is a rodent of the family Sciuridae, belonging to the group of large ground squirrels known as marmots. It was first scientifically described by Carl Linnaeus in 1758.