some forms of kennel cough are bacterial im lead to beleive so antibiotics would help but ive yet to see a vet check what type a dog has, there is a ton of it going round near me and now a case of lung worm, even the viral form can weaken a dog so it get secondary bacterial infections.
my pup caught kennel cough and i treated with benolyn and it cleared up within a week, but i didnt excercise him at all at is can put more stress on the respitory system making the cough worse.
if your dog is still coughing give it a bit longer theres still plenty of time to get your dog fit