So sorry to hear about Luger. We are going through the same thing with our 8 year old boxer girl at the moment.
She was diagnosed with hypercalcemia in June and was treated with high dose steroids, antibiotics and diuretics. We thought she had been cured, but it all came back in September.
We don't know exactly whether she has lymphoma or a tumour as we decided against taking her on a 5 hour journey to the nearest vet hospital and subjecting her to loads of tests, only to give her the exact same treatment she is having now.
We too decided not to go through chemo as it doesn't cure her and would only give her an extra few months, and we felt they were for us, not her.
So she is now on 6 steroids a day, down from 8 recently, diuretics to help with the bloating, anti sickness tablets and antibiotics. We don't know how long we have with her.
I hope Luger is doing well and you are able to keep him comfortable. We have so many questions, but don't know anyone else who has gone through this.
Big hugs to Luger, hope him and Sasha have many happy days ahead of them.