Board Thread:Questions and Answers/@comment-24826159-20140416214618/@comment-1268838-20140416223145

This is a bit of a complicated issue, but I guess the answer is technically "yes," even for Menos. Whether that Arrancar's persona bears any resemblance to the original human is another matter entirely though. There just isn't enough information to say.

Edit: Right, forgot about the lizard and dog. Animals do have souls, albeit rather insubstantial ones (as the cockatiel's was stated to be). But I very much doubt that animals get Soul Burials like humans do. Perhaps those animal "Pluses" can become Hollows as well? This is the kind of stuff that the series doesn't really acknowledge outright.