We just went through this yesterday with my parents' dog, only she was in a lot of pain at the end. I know it was the right time but it's still hard to see them go.
This happened to the first cat my family had, but he didn't have long left when the symptoms were there. He just came inside and something seemed off, we took him to the vets and they kept him for a while until they figured out what was wrong. I cried for days when he had to be put down.
Eventhough it's almost a weekly (sometimes daily) thing at my job and I usually think that I'm hardened to this stuff, I cried with a customer of ours last week. His care and love for his cat were so pure (probably especially since his wife died) but we found huge tumors. The moment he got the news he really broke together also because he wasn't prepared for it. And that was the first time I honestly fellt so sad for not being able to save a cat. I always remind myself that a time will come for every living thing but that wasn't enough last week
Why... ;-;
:(
im sorry for loss