When do you know when it's time to put a beloved pet to sleep? Our 13 year old husky/malamute cross Timber weighs 135 lbs. All of a sudden yesterday he can't seem to use one of his hind legs and can't make it up the stairs anymore to be in the house. We have put him in our heated garage for now. I let him out to go to the bathroom a while ago but he only hopped a few feet and laid down. He won't eat either. His mother lived to age 12 and lost the use of both back legs overnight. The vet said it was some sort of tumor in her spine and that she was too old to operate on it so she had to be put to sleep a few years ago. I am hoping that Timber doesn't have the same problem. Last time he was at the vet's she said he was in good shape except for an immune deficiency that makes him go almost bald twice a year. DH says it is time to put him to sleep but I don't want to do that unless it is absolutely necessary..