Well I thought that but vet said it only takes 2 day sto incubate slightly puzzled because the show would make sense.Hmm
A quick search of the internet suggests between 3-14 days incubation with one vet site not giving a specific period but stating that as there are a number of different causes and more than one could be involved, incubation can vary.
kennel cough incubation timeWhen one of mine got it, it was exactly a week after she'd been to a show where I'd heard a dog coughing. 7 days later the other two started coughing as well.
I used Baby Benylin and as they were snuffly, put a drop of olbas oil on their soft collars.
Hope your baby is better soon