Sounds like the pup is having a mad half hour to me. All of my dogs have done it and Id be very upset if they didn't. I think its great fun. Theres nothing wrong with it as long as noones being knocked over. Only thing I can think of is taking him on a stupidly long walk. Some pups will grow out of it however the peterpans among them wont. id lust enjoy it while you can. as for leaving the dog alone for 3-4 hours, i shouldnt worry about that either, if they get used to it while they are pups then they should have no problems when they are older. Many dogs love being alone to rest and escape the nightmare that is humans. Mine do.