We had our first warm (upper 70s) weekend and Mac didn't do so good. We went to play with a friend and she wore him out in less than a half an hour. After chasing the balls and each other he said "I've had enough" and went to lay on the cool concrete in the shade and drink water. The next morning (while it was still cool) we went for a short walk and again after sundown, both times he seemed to be panting alot and didn't show his normal energy. He is only 4 1/2 years old, the vet says he is good shape. Are the rest of your babies so easily affected by the heat? And does anybody know how I can get him ready for the the upcoming summer?