I think we have sidetracked here a little.
Animals are intelligent. They are capable of problem solving showing empathy and emotions.

The question is whether your soul would be ripped apart for being responsible for the death of
a) a dog
b) a dolphin
c) a monkey/chimpanzee
d) a house-elf
e) a goblin
f) a centaur
g) a unicorn

I don't think a wizard's soul splits if they are to kill any of the above, according to my recollection of the books.

This is a different sentence - to - people shouldn't randomly kill living things (which I certainly agree with, and would suggest the good guys of the HP books also agree with).... hopefully there will be no hysteria as a result.