So sorry Cameron, to lose two dogs in such a short space of time too.
My mum had a little Sheltie, it had heart problems, but was on medication and was fine. One Sunday my Mum rang to ask if I could go and get Kindy. Not unusual, as I minded her if mum was off out for the day. But on this occasion, it was because Kindy needed burying in our field. Mum had got up, taken Kindy a walk, she had eaten her breakfast, all fine. My mum looked round and she was dead in the middle of the kitchen. It was such a shock her going so fast. But her heart must have given out, but nice the way she went.