Shalom,   There is a distinct process for each spark of soul  that has to return, whether human , animal, plant, or mineral.   For more information as to the details regarding what happens to an animal or to a specific nefesh we, wouldhaveto look in the Shaar ha Gilgilum / known as the gates of transmigration or Reincarnation.   There is a nearly full translation of this work from Kehot Publishing.  I would recommend you consult that work.   The answer to your question is rather detailed and substantive.  After reading the Gates of Reincarnation which isn’t a very long volume you should have a better grasp of the subject.   Best wishes—   R.Yosef Karpman