
Kennel cough is a virus and as such antibiotics has no effect on the disease itself. Although antibiotics are sometimes given to treat or prevent secondary infection, such as a chest infection, the course of the virus just has to be left to run through. As a respiratory virus KC is very infectious so, just in case that is what it is, you need to keep your dog well away from others for at least a week after the ceasation of all symptoms. It can be very serious, fatal even, for the elderly or the very young. I doubt there is much use in trying to keep him apart from your other dog as, if it is KC, she is likely to be already incubating it. You need to keep her away from other dogs just in case too even if she never shows any symptoms. If a cough develops you can give Merlin some relief by giving him paediatric Benyln although I don't think it would be of much use for sneezing.