I'll admit my ignorance on this: I don't know of any doctrine of any religion concerning animals' ability to dream or imagine.
Nor do I know of any doctrine saying animals don't have souls.
I neither speak nor read Hebrew, so maybe somebody who does could correct or amplify this, but as I understand it, Judaism uses 5 different Hebrew words for soul:
Therefore (as I understand it) animals have a "level" of soul (like, maybe, nefesh and ruach?) which coresponds to the Catholic/Aristotelian idea that animals have an "animative" soul --- including, I'm guessing, dreams, emotions, imagination --- but humans have a "rational" soul.
So Catholic teaching doesn't deny that animals have souls. And its stance needs to be clarified, according to: http://www.all-creatures.org/ca/ark-186soul.html>
Pope John Paul II explains that animals have souls according to their nature (an animal nature.)
A righteous man knows the soul of his animal - Proverbs 12:10
This corresponds to the idea that animals do not have moral responsibility. You can't put an animal on trial for what it does or fails to do, because it lacks accountabilty; it's not "answerable" for what it has done.
Humans are "answerable" for their actions because they have the intellective capacity to deliberate and choose.
If you said animals had "rational" souls, you'd have to hold animals legally or juridically accountable for their choices. But they don't.
Does this make sense?
From a cursory reading, yes, and thank you!
I’ll post questions if I have them, after poring through your reply in detail.