Rex ( December 16 , 1984 -- August 31 , 1998 ) was a Cavalier King Charles Spaniel owned by Ronald Reagan and his wife Nancy during his term as President of the United States .
Rex ( December 16 , 1984 -- August 31 , 1998 ) was a Cavalier King Charles Spaniel . He was owned by Ronald Reagan and his wife Nancy during his term as President of the United States .