This article is from the Canine Medical Information FAQ, by Cindy Tittle Moore with numerous contributions by others.
This is characterized by a harsh, convulsive cough. It is persistent,
contagious, and often develops into secondary complications, such as
chronic bronchitis. This disease can eventually be fatal especially in
the very young, very old, or already ill. If your dog is exposed to
many other dogs, or will be boarded at a kennel, it should be
vaccinated against this. It is so-called, because it spreads rapidly
under "kennel" conditions -- many dogs kept relatively close together.
"Kennel Cough" is a generic name for a set of symptoms caused by a
number of organisms. These include parainfluenza as well as
bordatella, as well as many others. Dogs vaccinated with the
bordatella vaccine can still get "kennel cough" because of all the
bugs involved, but it tends to be much less severe.
Bordatella vaccine is squirted into each nostril of the dog and should
be repeated semi-annually. Parainfluenza vaccine should be a normal
part of your dog's regular shots.
The vaccination is not effective for the first 24 hours, so if you are
getting your dog vaccinated because you will be boarding it, get it
done at least several days in advance!