What facts emphasize the hunger madness of these dogs?

From the text:

It seemed as though their bones would burst through their skins. They were mere skeletons, draped loosely in draggled hides, with blazing eyes and slavered fangs. But the hunger-madness made them terrifying, irresistible. There was no opposing them. The team-dogs were swept back against the cliff at the first onset. Buck was beset by three huskies, and in a trice his head and shoulders were ripped and slashed. The din was frightful. Billee was crying as usual. Dave and Sol-leks, dripping blood from a score of wounds, were fighting bravely side by side. Joe was snapping like a demon. Once, his teeth closed on the fore leg of a husky, and he crunched down through the bone. Pike, the malingerer, leaped upon the crippled animal, breaking its neck with a quick flash of teeth and a jerk, Buck got a frothing adversary by the throat, and was sprayed with blood when his teeth sank through the jugular.