Since July of 2008 Colorado Springs has had the dubious honor of being host to a widespread outbreak of canine influenza, an emerging disease in dogs. Canine influenza was first identified in 2004 in Florida, although evidence looking back as far as 1999 shows that it was around then, we just didn’t have a way to identify it or a name for it.
The symptoms are typical of “kennel cough” which is a general term used to describe the hacking cough of infectious respiratory disease. There are seven different organisms that cause identical respiratory symptoms, but because the treatment for kennel cough is essentially the same no matter what the causative organism is we often find that putting the time and money into finding out exactly what organism it is may satisfy our curiosity, but usually won’t have much practical effect on what we are going to do about it.
A typical bout of canine influenza involves a hacking cough that starts four to five days after a dog has had contact with an infected dog or sneeze products that an infected dog has left behind. The cough tends to be worse at night and in the morning, and better when the dog is moving around during the day. It usually lasts for about two weeks, but I have seen some cases that hang on for six weeks. Most dogs feel reasonably normal and continue to eat and drink. A very small number of dogs become debilitated and need more aggressive supportive care, possibly including hospitilization to get them through. There is a form of the disease that causes a very sudden and overwhelming pneumonia that often becomes fatal within hours of onset. We have not been seeing the severe form to any significant degree in this outbreak in town.
Contagious diseases thrive in places where groups of dogs come together, and influenza in particular spreads between dogs with great ease. Animal shelters, boarding kennels, dog parks, and even your veterinarian’s office are great places to be exposed, and once one dog in the household gets it he will share with all the other dogs in the household. It would be considered good manners to not take your sick dog out in public until he is recovered, and if you are going to see the veterinarian it would be kind to let the receptionists know that you have a dog who could be contagious so they can arrange for you to not end up sitting in the waiting area while your dog exposes every other dog that comes in the door to influenza as well. Fortunately canine influenza only affects dogs, so people, cats, or any other species will not get sick from the dog.
Because canine influenza is a viral disease, antibiotics do not make it better. Sometimes we put our patients on antibiotics anyway to prevent secondary bacterial infections from piling on top of the viral infection and amplifying the problems, but to get the coughing to go away we just have to grit our teeth and wait for the dog’s immune system to learn to handle the virus.
The best way to battle viruses is to prevent infection with vaccinations. We already have vaccinations for many of the other causes of kennel cough. Parainfluenza virus, adenovirus, distemper virus, and bordetella, are in the vaccines that most dogs get annually. If you were wondering recently why your dog, who has been fully vaccinated, still got kennel cough it is because canine influenza hasn’t been around long enough to have had a vaccine made to protect against it. The shifty nature of the influenza virus makes it especially hard to pin down, so progress may be slow. The outbreak here in Colorado Springs has caused at least on major vaccine manufacturer to send a special team here to collect samples from which they hope to create a new vaccine. In the movies the handsome, brilliant epidemiologist would create the vaccine in 5 days, but in real life the time frame is probably many years.
Sometimes press releases tend to portray this outbreak as apocalyptic end times for all dogs as we know it. Admittedly that is much more dramatic sounding than the reality that canine influenza is a nuisance for a couple of weeks, and then most dogs recover without looking back. Speculation that it will jump species and cause a second deadly human influenza pandemic is also great for inciting hand wringing, but the virus would require several major and unlikely mutations to do that. If we are lucky we will have a vaccine soon and there won’t need to be much discussion about it at all.