My heart goes out to you. My dog Harry has cancer as well, but he's on Palliative care because his is very advanced and I've chosen not to put him on chemo after watching what my brother went through with 2 of his dogs. I lost another dog in January, the love of my life really after doing every possible medical intervention that could be done, and in the end he just didn't want to keep going. His little 15 yr old body was worn out. This was at the same time I found out about his brother Harry. Harry is actually in no pain and mostly has good days. He does have an apetite still and loves his walks and quiet times with me. He still loves sitting in the sun more then anything and being brushed and pampered
I am breaking all the rules now with him and feed him whatever I'm making for dinner...I make an extra serving of the protein for Harry and give it to him away from Sunni, so he can enjoy it in peace. This is such an individual and difficult decision for anyone to make, and there is no right or wrong way in my opinion as long as you are doing your best for your baby and keeping him out of pain as much as possible.
I do think that when the time comes your dog really does let you know. I know my little George did. I was trying beyond beleif to keep him alive, but by then he was blind and losing his hearing, I think the surgery at that late stage of his life had a huge effect on him in a negative way. He was so confused by his surroundings and if I wasn't near him he would whimper. Harry would lay with him..it was a very sad time. Still is..But I know George knew how much he was loved..I held him close to me as I said goodbye and he just went to sleep in my arms, hearing me tell him I love him and always will. Its hard. I'm praying for you and your sweet William..my heart goes out to you..xox