You're not likely to reincarnate as Fido as much as you think you'd like to be able to lick you-know- where. And Fluffy is not likely to reincarnate as human because why would she having already reached the pinnacle of Earthling experience as Animal? From a different perspective we're here to follow not lead. And therein indeed lies the difference in Soul.
Thanks for listening! the Animals say "Together we are One."
