Its a matter of life versus choice.
If an animal attacks a human, it is because it needs food. Sometimes, though mostly rarely now, the other way around occurs with humans hunting animals.
Now take any ordinary hunter, or someone who just abuses animals...with the methods today, our weapons, etc...it is purely for sport and killing, assuming you are the superior, and what you put them through is just for your entertainment. People with any disregard for life as to think that killing any random dog is less bad than killing any random human is wrong. They are still killing either way, and one usually may lead to the other.
Its just the way we think of it. We cant imagine veiwing things through the eyes of an animal. We just see the object, that moves around and barks or whatever. They think, if only with the intelligence of a one-year-old, although some are more intelligent than others. This is the age of robots and machines, we think of animals as machines, not really living.
If you abuse animals, you likely abuse humans as well or will. And you're probably a shitty person too, in general.
Now I dont think torturing animals is any better or worse than hurting humans. It has to do with innocence, and choice. We choose to kill/torture(either innocent humans, or animals), out of our own choice. When we fight eachother with guns or whatever, it is out of mutual consent (or nonconsent)- we choose poorly and end up fighting (animals do this to eachother too)- I cant feel any pity for them. But when one person decides to kill someone who is just innocent, or even an animal, thinking it is alright, theres a blood rage at hearing that. Those people I hate.