. Took Milly and Poppy out for their walk/run on Monday and everything was ok, Tuesday Milly wouldn't eat her breakfast and was sick during the day. I assumed that she had eaten some rubbish so I took her to the vets this morning and got the devastating news that she has chf (heart failure) and is critical, in pain and recommended putting her to sleep. She can only stand up for a few minutes. Milly is 13 on 1st May. What do I do.