While true -I am a football fan- that doesn't enter the equation. I'd stand by my statement if Michael Vick was a cashier at Wal-Mart, a factory worker, a farmer, or leader of the free world. I'm also an animal lover (though not quite to PETA levels), and I cried like it was a scene from Ol' Yeller when I had to take in my Lab to be euthanized a few years ago.
How much "value" we place on the life of an animal varies widely within a culture, let alone between different cultures. In many cultures, animal fighting is embraced as entirely normal. Examples include cock fighting, bull fighting, etc. Its not for me, but I could likely convince few people in Indonesia that this is unacceptable.
We routinely bleed-out cows and turn them into tasty steaks and burgers. Chicken, turkey, sheep...the list goes on and on. Obviously, as a society we value their lives less than human life. So where is the line draw when people choose to mistreat animals for sport? Some would argue "an eye-for-an-eye, let's set the dogs on him". Others would argue "what's the big deal?". So, as a society we must determine the appropriate punishment. Something between shrugging our shoulders and the death penalty.
I have seen people convicted of manslaughter (as in, the slaughter of a man (or woman)) allowed parole with little or no jail time. Michael Vick served roughly two years. Granted, manslaughter generally infers lack of intent to harm, so there is a difference on that ground. If our society as a whole no longer feels his punishment is adequate, then they only way to alter this is by forcing the hand of lawmakers to increase penalties.