I have a fox terrier mix that's about 5 months old now and a little over 9lbs. Since we've been able to go on walks (after he got all his shots) we've gone twice a day at 8am and 6pm. Each walk lasts at least an hour. Lately he's seems pretty tired and today at around 5:15 I noticed that he had fallen asleep. I decided to just let him nap and now it's almost 7 and he's still sleeping. Am I walking him too much? I wanted to make sure he was tired so he's not so hyper when I'm gone during the day but he just seems too tired. Should I walk him only once? Or should I cut the time in half?