The coverage of the Michael Vick dogfighting case has focused on the repercussions of his actions on his NFL career. It is focused so much so that some journalists have claimed that he would not be given as hard a time if he had simply killed someone.
This hyperbole does not help in the discussion because it begs people to downplay the manner in which the animals died and overemphasize the exceptional cases where someone's death results in light penalties.
These animals were intentionally raised to kill or be killed in excruciatingly tortuous ways. If the losing dogs did not have the good grace to die in the ring they would be killed in ways that seem calculated to be the most cruel. Drowning? Hanging? Electrocution? Hanging and electrocution may be state sanctioned methods for executing criminals according to strict guidelines meant to limit suffering (as if anyone actually knows, but capital punishment is a whole other can of worms), but when administered by laymen, one must assume that they were not so careful to avoid suffering.
Here's a BBC article on dogfighting and its rise in America.