I took the dogs with me to go swimming at Anne's today.  The predicted high for the day is over 100 F so the pool was very inviting.  The entire time we were there, Charlie was in and out of the pool.  He chased kids and balls and even tried jumping (carefully) off of the steps.  He had a great time.  I'm sure he was smiling, but he was panting so hard it was difficult to tell.  He didn't stop the whole time we were there. When we got home, he crashed in the middle of the dining room floor and didn't move for the rest of the night.  He was exhausted.  He wasn't even particularly interested in eating dinner... but he did manage to muster enough energy to eat and climb the stairs to his bed where he slept soundly all night long.