I do not consider animals “not conscious”. I consider many animals to have consciousness. One way or another, in my personal moral framework I also treat animals as if they are conscious.
Why do you assume otherwise?
I simply answered your first question on the premises you laid out: that even if a person did not believe animals are conscious, there are good reasons for a Catholic to treat them well. Surely you WANT all Catholics to treat animals well? It seems counter-productive to me to try to argue Catholics out of believing there are good reasons to treat animals well that aren’t based on them being conscious – because regardless of what you and I believe, there are bound to be plenty of Catholics (and atheists, and Hindus, etc) who won’t be aware of (or care about) contemporary scientific consensus. So you can’t insist that people have to have reached the same conclusions as you for the same reasons. Can’t you just be happy when people share the same conclusion, regardless of the reason?