I am so sorry to read about Riggo. My first boxer, Bailey, went through chemo for lymphoma with hypercalcemia. Chemo was very effective at putting the cancer in remission. Bailey did well with the treatments, but after over one year her liver began to fail from the drugs. Up until her liver problem Bailey had hardly any side effects from the chemo. She was playful and energetic and loving as ever. I would suggest that you check into starting Riggo on some supplements to help protect his vital organs, if you haven't done so. You can find some good info on this site about that, as well as good diet info for cancer dogs. I wish all the best to you and Riggo.