We lost our 13 year old pug Trixie on Friday.
She would have been 14 in October, was still going strong, albeit less active the past few years. It happened while we were on vacation with the whole family too. Huge bummer, but still the same time thankful she was with us and not locked up in a kennel several hundred miles away.
The kids were really sad at first but seem to have bounced back quickly, bless 'em. The wife and I are still pretty broken up about it though, we got her shortly after we moved in together and she was there for our wedding, two daughters, and survived two major surgeries along the way, including the emergency removal of her gallbladder. (We are still paying for that one)
Happy we got to enjoy her for as long as we did, trying to focus on that and not the end. Also helps we still have another dog Howie we rescued a couple of years back who is still going strong.
But yeah, most upset I've ever been over losing a pet. Just a fixture in our lives suddenly gone...