Corn Snake Attacked by Cat

Question
I Have a 2 1/2 year old corn snake approximately three feet long (until this morning).  My cat caught the tip of his tail and pulled him through the wire cover of the tank and chewed approximately 6-8 inches off him.  He is still alive.  I cleaned the stub of the tail with sterile water and applied polysporin.  Someone told me he won't survive if he has lost his tail up past the cloaca.  I can't find an opening on his underside, so I can only assume it has been severed.  Is this true and is there anything else I can do for him?

Answer
Taking him to an Veterinary Hospital as an emergency case is your first step.  He must be in terrible pain.

A vet will be able to determine whether he can survive the injury, and if not, euthanize him humanely.
If he can be saved, he will certainly need antibiotics--not just topical ones.

Reptiles can live with mortal injuries for a long time, but he shouldn't be forced to--they feel pain as much as any vertebrate animal.