Hello there, I'm so sorry this is happening to you.
About 8 weeks ago my wife's mastiff cross was diagnosed with a tumour on his shoulder. He too had a history of arthritus and had already been through several ops and had replacement joints. He was fantastically and expensively insured and our vet talked us through the options. Chemo, amputation etc. There is nothing we wouldn't have done for that dog and had any of the options given him any quality of life, we would have gone for them.
Our vet was very straight with my wife about the fact that if it was his dog, then he would have him pts. The second vet at their sister surgery where he went for a scan to confirm his tumour said the same. He would have maybe had another 6-9 months but his quality of life would not be good and it would be 6-9 months of treatment and illness with some good days.
Also, and I really hate to say this, but I think I should, we were advised that if the tumour was growing through the bone then there was the possibility of a traumatic break at any time. His initial diagnosis was on the Monday, on the Tuesday he went for a scan, a tumour was diagnosed straight away and my wife decided that he shouldn't be brought round and be pts while still under anaesthetic. His quality of life would have been, for him, too compromised. He died peacefully and gently.
She was and still is utterly devastated. And he was also only seven. Unfortunately this is something that apparently is common in large breed dogs and she'd been through cancer with her previous large breed dog so knew what treatment looks like.
I'm sorry I can't give you more hope. I can only tell you our story and tell you that she and I feel strongly she made the right decision. He didn't suffer, he didnt undergo months of pain and while we weren't ready for him to go and it was very sudden, we did the best thing for him.
Again, I'm so sorry you're going through this.
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