Animal abuse penalties should be made the same as for abusing a human. Then the penalty for abusing a human should be changed to be higher than it is now.
Even abusers of human beings do not always go to jail. Most of the time, actually, they don't.
In general, the law comes down way too hard in some cases, and not hard enough in others--for example, a teenager caught with a bag of pot can get the same penalty as the same teenager killing somebody in a gang shooting. (I'm saying teenagers because in the case of juveniles, the law is especially inconsistent... but the trend holds: Drug offenses are often punished way more than violent crimes, when it's the violent crimes that hurt people much more directly.)
Fact is, the law will never be perfect, especially in the case of animals, children, and other creatures that don't have a vote. That's why those of us who are old enough have got to stick up for those who can't or will never vote. Even a letter from a private citizen can make a difference--I know, because when I was 14, I wrote a letter of appreciation to a Congressman who helped ban partial-birth abortions in Missouri; and I got a personal reply. And I think it was the Congressman who wrote it, too, because he thought I wanted to be a politician! Of course, state congressmen aren't as big-time as national ones, or senators; but aren't those sorts of laws made on the local or state level most of the time, anyway?
I mean, if a 14 year old kid who can't even vote, can get a state congressman to read a letter, surely other people can, too.
What I've always said... Being stronger and smarter gives us the responsibility to protect creatures weaker than us--not the right to use them however we see fit. An animal's life will never be worth as much as a human's in my eyes; but it is certainly not worthless. When you own an animal, you enter into a contract: Take care of its needs; treat it with kindness; train it appropriately; and, if you must kill it, then kill it humanely.
That principle has been around for a long time--there are animal-abuse laws in the Old Testament, such as the law that one cannot muzzle an ox while it works on grain, so that it can take a mouthful to sustain itself... Or the law that one must make restitution for an injury caused to another man's animal... The law that animals must not be strangled to death (and the fact that kosher-killing an animal is nearly painless)... It's a lot of dry reading and archaic legal stuff; but there are a lot of gems in there, and a window into how people lived back then.
We've always known that we had responsibilities towards animals... but there have always been people who ignored them.