Amazingly enough the Lymphoma will make the decison for you. The median time of survival for Lymphoma in puppies is 7.5 months. The general rule is that each remission will be 1/2 the time of the previous remission. Depending on the protocol or drugs used often determines the initial remission.

As time goes on you will run into the phenomena called multiple drug resistance or MDR. This will necessitate switching to a rescue protocol. These typically involve drugs that can severely depress the bone marrow, leaving the dog open to a secondary infection.

My Daisy dog was diagnosed with Lymphoma on 03-Jun-2002, and after a year of Chemo including a 7.5 month first remission she died on 05-Jun-2003. She was playing in the yard at 2PM, and then could hardly stand up at 4PM. With no effective Chemo treatments left, and the infection still raging 24 hrs later it was an easy decision. Easy but heart renching. It is frequently the case that a Lymphoma dog given Chemo will crash hard and quick. So there are no long periods of suffering.

My advise to you is to continue pursuing Chemo insisting that supportive drugs such as Metoclopromide (or Zofran for severe nausea) be given, and to be aware of any signs of secondary infection. In the meantime continue to give your dog as normal of a life as possible engaging in the same activities as before it became ill. Cherish the time.