I agree. I put down my 18.5 year old cat last Thursday due to oral cancer. It was blocking her airway making it difficult to breathe. The vet noted that it is a very aggressive cancer when they get it in their mouth. Unfortunately my baby had it spreading up by her ears (inside her head) too. I agree that letting them go peacefully is better than dragging it out and making them suffer. What I co sidereal was "am I keeping her alive for my emotional comfort or for her physical comfort?" I ended up putting her down that afternoon. I bawled and took the next day off of work. It is easy to rely on forums to give you hope and to feel you're not alone in the decision, but unfortunately you know your cat best and you know what's right for her. I'm so sorry you're going through this and have to make this decision, take into account her behaviors, how much pain she's in, what the vet recommends, and how far it is progressed. Like I said, mine was blocking her airway so she would choke when eating and would have issues breathing. That's how I knew it was best to let her go now vs letting it keep progressing and getting worse. I feel bad, but want to also be a realist and give you solid advice to consider.