I cannot yet tap into any past live memories to try and verify anything about reincarnation myself. However there are traditions that talk about the process of getting to the stage of remembering past lives as more than just glimpses under hypnosis. In some of those traditions I’ve made progress and can verify other aspects of their systems. None of the stuff that has proved in part legitimate to me has suggested that beings ever reincarnate into other species.

In multiple traditions they talk about forgetting past lives as a blessing. Most cannot handle the weight of their past lives in addition to the present one.

As far as the lower beings and sentience, yes there is a process where by they can grow and develop but it’s a very long process. We will get to be a part of the process and cats/dogs are supposed to be the next group to gain individual consciousness.