We took a longer walk than usual yesterday and we haven't been walking regularly because it's been so cold. George always trots along full speed, minus the p-mail stops , until he's had enough and then stops dead and doesn't want to go any further, even if we're still blocks from home. And he did that yesterday, too. When I finally did get him home, creeping a few steps at a time with great reluctance on his part, he flopped down on the deck and had to take a nap to get rested enough to come in the house, where he slept off and on all evening and all night and is still doing it this morning. I'm worried that we way overdid it, though we only went about three blocks further than his usual walk and he was very energetic and eager during the actual walk until the Full Stop point -- but he ALWAYS does that same thing, and nothing was different about it yesterday. He's 8 years old.