Dude, I feel your pain. I had to put my dog Molly to sleep about a year and a half ago. She was 8 years old and got cancer. We treated her the first time with surgery, and she ended up lasting about another 6 months after that. I went out to feed her and my other dogs one day, and she had a seizure. I called the vet immediately and they said if she had anymore, to bring her in. She had another one about an hour later and I lost it b/c I knew what I had to do. The cancer had spread to her brain. It really sucks to have to make that decision, but it's the best thing you could have done....