This is my thoughts on what happens when an animal dies. When I used to be a Christian they always talked about the afterlife and I always wondered what happened when an animal dies. Now I think I have I came up with an answer after reading "Animal Spirit Guides" by Steven D. Farmer.
I believe that when an animal dies it goes to the afterlife and is given the task of guiding and sending messages to us humans animal spirit guide. As for pets, I think that they are given a choice whether to become a spirit guide or spend the afterlife with their human family.
There are all sorts of viewpoints out there when it comes to this topic. Especially if you start considering what lines or grey areas may exist between animals that may or may not be developed enough to be able to have or form some version of a soul.
For example, Ants are individually very simple creatures, literally referred to as drones because of their lack of individual behavior and basic brain and nervous system. But, at the same time ant colonies have a collective skill and intelligence that defies their physical limits. Large mounds have mushroom farms. They incorporate drainage. They assemble tunnels and chambers in a way that provides climate control and even induced airflow. They take other species of ants as slaves even. Through this it gives merit to the idea they might not have individual soul... but instead a collective consciousness.
Also, might a soul itself not grow and evolve? Maybe a new soul would begin simply... gaining experiences in the raw through a simpler mind and form. Then as the soul forms pieces of consciousness it may step up to newer, more complex, higher order beings.
And still it makes more questions. When might a soul determine it wants to remain at a particular order... say choosing to remain a fox rather than expanding to wolf or human even. Could a differing order of being even redefine itself as something like a human? Or are they too different and on their own unique path of evolving?
Personally I am always full of a big list of maybe's and contexts. But finding a solid theory has been much more elusive for me.
Not always. :P :)
There are spirits which are literally like cats and dogs in the spirit round, but they have humanod forms too. There are spirits whoch just choose to incarnate in that type of bodies.
You could surely incarnate as a cat, as a serpent or any type of creature. That though, doesn't mean you will be given the task of guiding others. Remember, soceities exist in the spirit worlds and much more complicated but you're not forced to do what you don't want to. Some spirits could guide yes, others live there and rest...
Either pets or creatures that aren't in a humanoid body (eg dolphins) or even humans; this is no difference. You do what you want to. :)
I was just doing research on Familiars, and it is possible for an animal to die and then become a familiar, so your theory, is very possible, in fact, that's what I have come to believe as well