The words are often used with definitions that differ greatly. Can we get these defined as we can observe in biology?
Consciousness gives rise to experiences and memories, all of which makes up our personality. Is consciousness the cause or is consciousness the result? Is consciousness the proof of some otherwise undetectable causal force? "Spirit" or "soul".
So then do all conscious creatures, great and small, thus have a spirit or soul? Science can't say much on this subject since we can't test things beyond our observation. Do we leave the discussion up to religions? King James mentions that man has a soul but does not use this description when discussing other creatures. Other versions of the bible use much the same language for creatures as it does for mankind. Non-biblical religions have their own views. I don't see much of a consistent conclusion other than that we do exist.