The story is similar to what I have heard many years ago about "wolf child". Wild wolf raised abandoned human child through breastfeeding and then they hunted together as a pack when the kid was older. Not sure how true the story was, but the story of "wolf child" came up on more than just one occasion.
Cross species nursing in general are amazing stories if they are true. I guess dog milk and wolf milk actually met the requirement of a human baby. It is hard to imagine though how the child's nutrition requirement could be met by dog diet or wolf diet alone. They are carnivore, so they can live on nothing but meat. Humans need some veggie and fruit to be healthy. There are just so many vitamins and minerals not available from meat alone.