Bordetella has earned a couple of distinctions in veterinary medicine. First and most important, the vaccine against the bacteria is among the most controversial in the profession. Expert opinions on the use and benefits (or possibly lack thereof) of the vaccine vary wildly — more on that in a moment. Second, Bordetella is without a doubt the most frequently misspelled word in veterinary medicine. Few people remember to italicize it. Most people — even vets — misspell it “Bordatella.” And over the years plenty of folks have taken to calling it “bordello,” which in my opinion is quite a funny malapropism.
Let’s talk about the Bordetella vaccine — or rather, vaccines, because there are three commonly used varieties. To understand the vaccines and the issues surrounding them, one must first know a bit about the bacterial infection they are designed to prevent.
Bordetella bronchiseptica is a bacteria that is linked to a condition called infectious tracheobronchitis (ITB) in dogs. Another member of the Bordetella genus, Bordetella pertussis, has earned quite a bit of notoriety over the years because it is the cause of whooping cough in people. The canine Bordetella appears to pose minimal risk to humans, and the human Bordetella likewise does not appear to pose a risk to dogs.
Infectious tracheobronchitis is known colloquially as kennel cough. It is an extremely common syndrome in dogs, characterized by dry honking coughing that can be triggered by stimulation of the windpipe. The coughing is contagious, but usually only to susceptible individuals (this means that not all dogs exposed to kennel cough will develop the syndrome). Crucially, the coughing is generally self-limiting. True kennel cough is not life threatening, and frankly it’s not a very big deal, unless one happens to own a kennel in which the syndrome is spreading (it turns out that dog owners don’t take kindly to their pets contracting diseases — even minor ones — in kennels).
Bordetella bronchiseptica, especially in dogs coinfected with canine parainfluenza virus, is a common cause of the syndrome. But it is far from the only cause of it. There are dozens of known viruses and bacteria that can cause transient tracheobronchitis. There are probably many dozens of additional bugs that have yet to be discovered.
As I mentioned, infectious tracheobronchitis is contagious but not every dog that is exposed to it will develop symptoms. Many dogs’ immune systems are capable of warding off the infection before any coughing occurs. The kennel cough colloquialism developed because kenneling situations provide ideal environments for the syndrome to spread: large numbers of dogs are housed in close quarters and are stressed (because they’re away from home), leading to weakened immune systems and therefore increased susceptibility to infectious tracheobronchitis.
So, what about the vaccines for Bordetella? There are three commonly used types: an intranasal vaccine, an injectable vaccine, and an oral vaccine. Over the years there has been plenty of debate about which is the best.
Studies have shown that the injectable vaccine leads to higher antibody titers against the bacteria. However, these titers don’t necessarily give a complete picture of immunity. Bordetella is contracted when the bacteria contacts the respiratory mucosa (which consists of special cells in the respiratory tract). The intranasal vaccine, which is administered in the nose, appears to be more effective at creating so-called mucosal immunity, and as such may offer better protection.
Studies have also shown that the intranasal vaccine leads to a much faster immune response. Dr. Richard B. Ford, an expert on the subject, wrote in the November/December 2013 issue of Today’s Veterinary Practice that “dogs administered a single dose of intranasal vaccine have been shown to derive protection within 72 hours,” whereas injectably “administered vaccines require two initial doses, two to four weeks apart (a single initial dose is not considered protective); onset of immunity takes at least two weeks and a few days.” To date, there has been little research on the oral vaccine.
The best way to administer the Bordetella vaccine has been heavily debated during my entire career. However, the experts now appear to be coalescing around the following strategy: Administer an intranasal vaccine first, followed by an injectable vaccine three to four weeks later. This protocol, in theory, will lead to a rapid onset of protection as well as a stronger “immune memory,” which will help increase duration of immunity. However, Dr. Ford was careful to point out in his recent comments that this theory has yet to be tested.
There are two additional controversies surrounding the Bordetella vaccine. The first one relates to how frequently it should be administered. The most common current recommendation is that dogs receive Bordetella boosters every six months. However, Dr. Ford points out that “there are no studies demonstrating the value” of doing this. He suspects that annual vaccination may be more appropriate.
The second controversy is whether dogs should receive Bordetella vaccines at all. The vaccines are designed to reduce the risk of an infection that is generally mild and self-limiting. And vaccination certainly doesn’t guarantee that a dog won’t contract kennel cough — as I mentioned, there are dozens of bugs other than Bordetella that can cause the syndrome.
Many boarding and grooming facilities require that dogs be vaccinated against Bordetella prior to entry. If your dog will frequent such a facility, then he or she will probably be getting the vaccine. But I do not generally recommend Bordetella vaccines as part of routine vaccination protocols for dogs that don’t frequent such facilities.
In that regard, I put my money where my mouth is. My pal Buster has received precisely one Bordetella vaccine in his life. Several years ago I thought I might have to kennel him on short notice due to a possible family emergency. I brought home an intranasal vaccine and administered it. Fortunately, Buster did not need to go to the kennel. And he hasn’t had a Bordetella vaccine since that day.
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