I'm sorry, Al. We have treated two of our dogs with chemo/radiation, and the progression seemed unpredictable in both cases, I think because it is a balancing act between treating the cancer and preserving the internal organs. You will know when it is time. I am getting emotional writing this, thinking about what you are about to go through. It's very hard, and the grief is very intense and long-lasting.
We have euthanized four of our dogs, two because of cancer, and we have always had at least one other dog at the time. We have done it at home and at the vet's office. It was always hard on the other dogs - they really miss the dog that is gone and the dynamics of the family are dramatically changed. Sometimes they have misbehaved afterwards, and one time we had to house-train a dog over again from scratch. It is important to give them a lot of love and attention, but also to simultaneously reinforce their place in the family, since it is natural for a dog to reevaluate his/her place in the pack at a time like this.
I can't say that I really noticed a significant difference based on where we had it done, and I'm not sure I'm such a believer in the "closure" idea. Our main consideration has been the dog who is being put down; we wanted them to be as comfortable and and content as possible in their final minutes. If they were still capable of enjoying it, we tried to give them a good day, spoiling them with treats. And if they were nervous or uncomfortable at the vet's office, we asked the vet to come to our home. When we have done it at the vet's office, our vet has scheduled it for the end of the day, when they have no other appointments. This gave us privacy and allowed us to take as much time as we wanted. For ourselves, we have had our dogs cremated, and retained their remains and some other things to remember each dog ... a bit of fur, a collar, a coat.
