Dog wont eat anything

Question
Help Please!!!!!!, My dog(huskey,lab mix) is 12 years old and has a big tumor on his liver. He has not ate anything for around 4 days, he has only been dinking a little water and still wants to go for walks. The vet said a year ago that she cant believe he is still living. Ive looked at a few storys on the internet and people say that an old dog that wont eat is most likeley starving itself to death, or not eating is the end of a dogs life. Do you have any advice, should i just put my dog to sleep?:(

Answer
One of the greatest, and most difficult responsiblities that we as pet owners have, is to help our babies go gently across the Bridge when the time has come. Liver disorders cause both humans and dogs to lose their appetites, Your dog has fought a valiant fight, and you as his guardian have helped him to do that. It's now up to you to allow him to end his life gracefully and with dignity, with as little pain and trauma as is possible. Personally I feel that it is your decision when the time is right, however in my opinion, it would be now before his condition worsens or he suffers unduly. Dogs by nature don't tell us when they hurt,. they suffer in silence. Let him go peacefully with his head in your lap and he'll wait for you on the other side.
My  heart's with you
Cindi