kennel cough

[cathardy]

I have a nine week old newfoundland pup that started with kennel cough as soon as we brought him home. The breeder has confirmed that none of the litter have this problem and my pup seems to be the only one. My vet has put him on a very mild antibiotic because anything stronger could affect his bones and growth. However after nearly two weeks he doesnt seem to be improving. I have him in a small room at night and have just started to put a menthol vaporiser in there to help with this problem. He isnt showing signs of being ill, just the opposite, he plays and runs and eats well. However I am concerned about the coaugh and wondered if anybody had any ideas such as herbal remedies, etc