Its a possibility that your puppy has pneumonia. I remember when my first dog was about 4 months old the same thing was happening to him. I had tons of people tell me that it was kennel cough, but it just didn't seem right. I took my dog to the vet and come to find out, he had pneumonia instead. The vet told us that it started off as kennel cough but quickly grew worse. You should definitely take your dog to get checked out because it could be worse than you think. Hopefully it isn't anything serious. I wish the best.
