Basically all animals fall below us on the food chain; it has nothing at all to do with how cute they are or are not.
The way I see it, *all* animals are entitled to humane treatment while alive and a decent, humane death if that death is to be put upon them by humans. Even if they are destined for a slaughterhouse (cows, veal, chickens, pigs, etc.) they should be killed as quickly and painlessly as possible.
Electrocuting dogs and smashing their heads in just shows complete depravity. It is considerably quicker and easier to kill an animal with a bullet in the head or a slit throat; these guys weren't only sick fucks for hosting dog fights, they are mentally ill for getting off on killing these animals.