The laws preventing cruelty to animals are for the purpose of protecting HUMAN societies - not animal societies. Inflicting pain or cruelty without reason to an animal, is considered sadistic and a threat to HUMAN society. I'm sure most here would have no objections about swatting an anoying fly, but I'd be concerned if I found my son spending hours pulling the the wings and legs off of insects. It hints at a deviance. Sadistic cruelty to animals hints at a sociopathic tendancy, as it is not normal to gain pleasure by watching demonstrations of pain.
Laws against animal abuse are actually laws against HUMAN deviance.
And btw, I love animals also, but they have no rights under MAN'S law. Under God's law - who knows?