We are faced with this tough decision right now with our cat Marbles. She developed a lump on her underside about a month ago. It did not seem to bug her but we decided to get it looked at. She was diagnosed with cancer in her mammary glands but we also found that it has spread to her lungs. After X-rays we found that she only has 50% lung capacity now. She is on steroids now to help her but we know it is inevitable. It is killing us knowing that we have to make this decision.
We got Marbles 6 years ago from the Cochrane Humane. We were not even looking for a cat that day, I just decided to pop into the room with the cats to see them. Marbles saw us and came right over and started rubbing against my wifes legs. She petted her and moved on. My wife sat down and Marbles jumped onto her lap then just laid down and started purring. My wife fell in love right then.
Since then she has been the nicest cat, very friendly and loving to be around us. Every night she comes to bed with us, then when we fall asleep she takes off. If she was a typical cat that did not care much about us this decision would be much easier I think. It would still be tough but not like this.
Reading through the other posts from people that have gone through this is making it a little easier knowing that others have had to make this decision even though it is very tough.