Dog Fighting, If it is Inhuman...

Something struck me while following the dog fighting charges against Michael Vick. If dog fighting is inhuman, what about boxing? It is another blood sport, two humans fighting it out in a ring where a knock out is the most celebrated type of victory and most people who watch a boxing match are expecting the same. But it is a legal sport, followed by millions, million dollar pay days for the boxers, with a govering body. So if there is so much hue and cry about dog fighting, then why not against boxing? One argument that some might use is, in dog fighting, the dogs did not accept to fight, where as the boxers do it willingly. Well what animal gives its consent before being slaughtered and served as meat?