alexnell, I'm so sorry you had to be put in that position. I don't know for sure but it seems that 14 years is pretty old for a Lab.
We don't always agree with our Vet, but maybe he felt Toby was in so much pain and he didn't see any hope with the arthritis, being deaf, no appetite and the terrible sore. Maybe it would just prolong the suffering by keeping him alive. That is such a difficult decision to make, we had to do that last October with our 15 year old Schnauzer who had terrible arthritis, going blind, lost all control, and in terrible pain. I feel that you did what you thought was the best thing for all of you including Toby.
Jackie