There are four exam rooms along the hall leading to my office. The other day when I arrived at work two of the four had signs on their doors stating "No Dogs!!". No, it does not mean that we are transforming into a cat clinic (although there are moments during heartworm season where this starts to sound attractive...). Instead it means that we are going through another outbreak of "kennel cough" and have to sanitize some rooms.
Kennel cough is an unfortunate name as it is misleading. Being a nerd I prefer the far more accurate "infectious tracheobronchitis", but we nerds are an embattled and misunderstood minority. The main problem with the name kennel cough is the kennel part. Dogs can contract this disease any time they are in close contact with disease carriers, especially indoors, but not just in kennels. The easiest way to think of this disease is to think of it like the human common cold. Sure, schools and day-cares (i.e. kennels for kids) are really easy places to pick up colds, but anywhere you are mixing with other people can do the trick. The cough part of the name is occasionally also misleading as some people perceive their dog to be choking or gagging or retching, rather than coughing. This can be even more confusing because a violent coughing fit can lead to hacking up some phlegm or saliva, which can easily look like vomiting to the anxious pet owner.
But all of that notwithstanding, I am not going to change the minds of thousands (ha!) with one blog post, so for the sake of clarity let's keep calling it "kennel cough". Now that I have agreed to that I suppose I should explain what it is. I already tipped my hand above when I compared it to the human common cold. Humans may sneeze more than cough with it because the nasal passages are targeted whereas dogs almost exclusively cough because it hits the windpipe and bronchi, but otherwise the analogy is useful several ways.
Like the human cold, kennel cough:
1) Is very contagious, but not all individuals will be affected the same as some have immunity.
2) Is caused by a large number of different organisms. In humans it's only viruses. In dogs it's mostly viruses plus one bacterium (Bordetella) and something wacky that is neither virus nor bacteria called a mycoplasma.
3) Usually runs a course of one to two weeks and requires no medical intervention.
4) Can occasionally develop secondary complications such as pneumonia or bacterial bronchitis, especially in the weak, the otherwise ill, the very young and the very old.
Consequently, if your dog is just coughing but is still hoovering his food and racing around like the damn fool he is, please give your veterinarian a call before rushing down. We don't want to spread the bugs in the waiting room and can often triage these and give useful advice over the phone (colleagues, please don't send me hate mail for suggesting this). Sometimes we may recommend a cough suppressant if the cough is disrupting sleep or is otherwise distressing. However, we must see the ones that may have secondary complications. These dogs may be depressed, off their food and/or hacking up thick yellowish goo when they cough. In puppies any vomiting, diarrhea or nasal discharge at the same time as the cough is also a reason to come down.
One distinction between kennel cough and human colds is that we have vaccines for kennel cough. These vaccines primarily protect against Bordetella and some also cover a couple of the viruses. Because of the number of potential causative organisms these vaccines only help reduce the risk, they do not guarantee protection the way a rabies or distemper vaccine does. Nonetheless, risk reduction is still useful in high risk scenarios such as, you guessed it, kennels, dog daycares, training classes etc.. Many of these facilities require proof of vaccination as they want to reduce the chance that they'll have twenty dogs coughing simultaneously. The risk in off-leash dog parks is variable and usually quite a bit lower, although it depends on how nose-to-nose your dog gets. Think of it like playgrounds versus day-cares for kids. The daycare is a petri dish sitting in an incubator, but in the playground your child will only get more colds if they lick the slide or wrestle with their friends rather than swinging quietly alone.