Will Falconer, DVM Moderator
Oh, Tammy, this is indeed sad, but the timing would suggest your dog was already having the cancer at the time of vaccination. That's no excuse for them vaccinating an 11 year old for diseases that typically only kill puppies, but none the less, it's likely the vaccine aggravated an already existing cancer.
The greatest gift we can thank these dear ones for is just what you've received last week from his death: the conviction that you will never go down that same path again! Please forgive yourself. We all start out ignorant, and slowly learn as we go. Thanks for sharing your painful story and all the best going forward!