My lab/shepherd mix has cancer, ..

Brief：
She has lymphoma cancer and was treated with chemo two weeks ago, had terrible reaction, but did NOT go into remission (80% of dogs do!!). Has anyone .. 

She has lymphoma cancer and was treated with chemo two weeks ago, had terrible reaction, but did NOT go into remission (80% of dogs do!!). Has anyone had experience with this, and how long does she have?? She seems to be happy and playful (she is 13 years old). Will her dying be painful or will she suffer?

Its hard to tell how long she has. Typically an untreated dog would have 4 to 6 weeks. Chemo can extend the life for about a year. Since your dog was the exception, the chances are that she as the same life expectancy as a dog without the treatment. For quality of life, a pain management regiment will help greatly. Talk to your vet about what kind of pain management they'd recommend.

You should probably start coming up with a check list, of signs to look for to help you determine when to euthanize so that you don't extend her suffering. Things to consider would be: no longer eating well, depression, no longer wanting to play, excessive vomiting/diarrhea, etc. I'm sorry about your loved pet. My dog had cancer in jawbone. We treated him for 3 months & hated to put him down. Nobody can give you a date of death, as thats in Gods hands. And don't let anybody tell you cancer doesn't hurt, b/c it does. On the downside, cancer is painful. The good news is that they do have good pain medication for you dog. How long she has to live depends a great deal on how advanced the cancer has become and the type of cancer. There are different kinds of lymphoma.