The bacterium Bordetella bronchiseptica can cause symptoms often referred to as “kennel cough.” It is not the only cause of the hacking cough often associated with infectious tracheobronchitis, however. Canine parainfluenza virus and canine adenovirus type 2 can also lead to infection.
“Bordetella bronchiseptica is a well-adapted pathogen of the canine upper respiratory tract,” wrote Daniel J. Klein, D.V.M., when he was a professor at the Kansas State University College of Veterinary Medicine. “B. bronchiseptica produces proteins on its exterior that allow it to adhere to the surface of the respiratory tract tissue, and it secretes toxins that destroy or inhibit functions of normal cells within the respiratory tract and the immune system. Bordetella bronchiseptica is the most common bacterial isolate from dogs with kennel cough and can be responsible for causing the disease in the absence of any prior or concurrent viral respiratory tract infections.”
Many dogs recover from infectious tracheobronchitis on their own. However, dogs with compromised immune systems, abnormal respiratory tracts or exposure to other infection, may require treatment.
Despite the fact that most dogs will return to good health without medical intervention, virtually all boarding kennels, including those operated by veterinary clinics, require that dogs staying at their facilities be vaccinated against bordetella.
“I’m pretty sure the kennels, when they experience an outbreak, it’s an unhappy occurrence for them,” says James A. Roth, D.V.M., Ph.D., a professor of immunology at the Iowa State University College of Veterinary Medicine. “They want to do whatever they can to protect the dogs coming in. Dogs are crowded together, coming and going, bringing in new pathogens.”
The two types of Bordetella bronchiseptica vaccines listed on the American Animal Hospital Association Canine Vaccine Guidelines are deemed “noncore,” meaning they should only be administered if an individual dog needs the protection. To read more about the guidelines, revised in 2011, click here.
The vaccine containing live avirulent Bordetella bronchiseptica bacteria is for intranasal administration only. It is sprayed into the nose and cannot be given intramuscularly or subcutaneously with a needle and syringe. “A single dose should be administered in conjunction with one of the core vaccine doses,” the AAHA guidelines state. If, however, a high risk of exposure exists, puppies as young as 3 to 4 weeks can get the intranasal vaccine, depending on the manufacturer. The vaccine must be repeated annually or more often in high-risk dogs.
Some puppies and dogs will develop three to 10 days of coughing, sneezing or nasal discharge after vaccination.
The other vaccine, an inactivated-cellular antigen extract, or killed bacteria, should be given at 8 weeks of age, then at 12 weeks, injected subcutaneously or intramuscularly, according to the AAHA guidelines. For continuous protection, the vaccination must be given annually. “On initial vaccination, administration should be scheduled such that the second dose can be administered at least one week before exposure at a kennel, dog show, day care, etc.,” the guidelines state. This vaccine cannot be given intranasally.
Roth says that “in general, we would expect [the intranasal vaccine] to induce better immunity” than the injectable vaccine. “In general, a live vaccine in the respiratory tract is more likely to induce a natural immunity,” he says.
In fact, a 1981 study showed that the intranasal vaccine produced an immune response in 96 percent of dogs, according to Klein.
However, Roth says, “if the animal has already had a bout of bordetella, the intramuscular might do a better job.” The injection will boost the natural immunity created by the previous exposure.
One reason veterinarians and dog owners might opt for the injected vaccine is because the intranasal goes up the nose, as its name suggests. While there’s no health objection to putting it up the nose, Roth says, “I think the dogs kind of object to it.” Plus, “it makes it more difficult to administer and to be sure that it all goes in,” he says.
Now another option exists.
This third method is not mentioned in the 2011 AAHA guidelines, as it just received U.S. Department of Agriculture approval in April 2012. The oral vaccine is squirted between the gums and the cheeks (the buccal cavity), using a syringe without a needle. This vaccine, too, contains live Bb bacteria. It can be given to puppies as young as 8 weeks of age and needs to be repeated annually, like the others.
The makers of the new oral vaccine “demonstrated that when they gave it orally, they could culture the live bacteria out of the trachea,” Roth says. “You wouldn’t necessarily expect it to work if it just went down the esophagus to the stomach.” But the bacteria apparently cling to the tissue of the trachea. And that does the job.
“You want live bacteria in the respiratory tract,” he says.