I've never gone into this thread as I've always tried to not think about our pet's own mortality, but this morning we put our beautiful 15 year old cat Shaula to sleep. It all happened so fast but last week she seemed fine or at the least did a very good job of keeping her illness from us. She started breathing a bit more heavily 3-4 days back and spent a majority of her time in the bathroom where it's warmest. Took her in this morning to the vet and I guess her little heart was starting to give in and she had a lot of fluid building up in her lungs and stomach. Wasn't a hard decision to have her put to sleep but I am absolutely gutted. Roughest day of my life by far.