Kennel Cough...or is it?

I see a lot of "kennel cough" here in my county. I see so many coughing dogs because my local shelter is a mess, with little hope of getting better. Many dogs that come from high volume, poorly run shelters will come out with some minor upper respiratory disease. Even in high volume, very well run shelters you will see this from time to time. Most of the time it's no big deal. Almost all the of the adult shelter dogs I see that have a cough are better in 3-5 days.

But even dogs that haven't been to the shelter are at risk for kennel cough. Dogs that board, go to day care, visit the dog park or are on the show circuit can be exposed to this disease. As always, prevention is always better than treatment and knowledge is always the best vaccine, so here goes:

What is Kennel Cough?
We'll let's start with some definitions. "Kennel Cough", as a diagnosis, is a bit outdated. The current term is Canine Infectious Tracheobronchitis (CITB). That's because we now know that while the bacteria Bordetella bronchiseptic, can cause a cough, it is not always the primary problem. Canine parainfluenza, canine adenovirus type 2, canine herpesvirus, and canine reovirus are viruses that have also been implicated in causing an infectious bronchitis in dogs. Infection with bacteria can be secondary to these viruses. So, when a dog walks into my clinic with an infectious cough, what am I really treating with my antibiotics, the dog or the owner? (For those of you not in on the joke, many veterinarians will give antibiotics to known viral infections just to make the owner think they are doing something. And they are: wasting their the owner's money and contributing to bacterial antibiotic resistance!)

So how does CITB cause my dog to be sick?
The purpose of a cough is to clear mucous and debris from the trachea. The cough is a result of a failure of the body's normal mechanism to clear these products. The trachea is lined with cells that contain "tails" that beat in rhythm to move particles in the throat out of the way. CITB infection destroys these cells and the body's ability to keep the trachea clean leaving a cough as the only way to clear the airway. This can lead to infections deeper in the respiratory tree (the lungs) as the body can no longer move bacteria out efficiently.

How should this be treated?
The latest information I've seen indicates that antibiotics may shorten the course of the disease in most cases. However, you must remember that in many cases a virus is playing a significant role. Since, viruses are not responsive to antibiotics, they may not always be helpful.

Is there a vaccine?
Yes, however, which one to use is subject to a lot of debate. There are two different vaccine delivery systems for CITB: intranasal (in the nose) and injectable. Which one you should use depends on your situation and should be discussed with your veterinarian. The intranasal vaccine is thought to act most quickly, but not last as long. Many veterinarians recommend vaccination every 6 months with the intranasal variety. The injectable may take several days to work, but can last up to a year.

Does the cough always go away?
This is the hard part about this disease. At one time it was thought that if your dog caught the bacterial form of "kennel cough", then it would cough for the rest of it's life. We now know that ANY dog that gets CITB can acquire a permanent cough. This is because once permanent damage has been done to the cells of the throat they may never be able to properly clear debris again. Fortunately, this is pretty rare, but it means that dogs should be seen at the first sign of a cough to prevent permanent damage.