Elizabeth Eiler quotes:

Throughout Mesoamerica it was a common belief that a dog carried the soul of a newly deceased person across a body of water. According to the Aztecs, the first level of the Underworld was a place called Apanoayan (where one crosses the river) or Itzcuintlan (the Place of Dogs).

There are mystical, unbreakable bonds between all members of the natural world including humans and animals. Whether or not we remember or acknowledge this relatedness, it still exists.