Today we are going to tackle vaccinating for three respiratory pathogens as a group – canine adenovirus type 2 (CAV-2), parainfluenza virus (Pi), and Bordetella bronchiseptica (Bb). I consider all of these vaccines to be situational. In other words, some dogs need them, others do not, and deciding who gets them is based on the individual’s lifestyle.

If you are paying close attention to this series, you may have noticed that CAV-2 was also discussed in the post on essential vaccines. Let me clarify. CAV-2 vaccines that are injected under the skin serve two purposes, the most important of which is cross protecting against canine adenovirus type 1, which causes a very serious form of liver disease. This is what makes the injectable form of the vaccine a must for virtually every dog. Veterinarians don’t use CAV-1 vaccines anymore because this old formulation caused eye inflammation (blue eye). CAV-2 is a respiratory virus, but thankfully, injectable CAV-2 vaccines also protect against CAV-1, without the unacceptable side effects.

CAV-2, Pi, and Bb are all part of the kennel cough complex — a group of respiratory pathogens that cause some combination of the following:

  • A cough that produces a lot of phlegm
  • Nasal discharge
  • Difficulty breathing
  • Fever
  • Loss of energy
  • Poor appetite

Symptom severity can vary from mild and self-limiting to severe with a progression to pneumonia and possibly death without appropriate and timely treatment. Dogs that are stressed, have an underlying respiratory disease, come in frequent contact with other dogs, and/or have weak immune systems are at the greatest risk of coming down with kennel cough. Therefore, I recommend vaccinating dogs that attend shows or other “doggy” events, that go to boarding or grooming facilities, that are entering animal shelters, and that are at high risk for especially severe illness regardless of their lifestyle.

CAV-2 and Pi are included in many combination injectable vaccines (along with distemper and parvovirus). Dogs that receive these vaccines on a conventional schedule (i.e., three or four puppy vaccines followed by a booster at one year then every three years) are adequately protected. If this vaccination schedule is not followed in an at risk dog, for example when an owner elects to run vaccine titers, I think it’s best to switch to an intranasal vaccine that contains these pathogens (and Bb) and give it annually (intranasal vaccines tend to provide the best level of protection against respiratory pathogens, but the immunity does not last as long as when an injectable vaccine is given).

Now on to Bordetella. Because of their efficacy, I recommend annual intranasal Bb vaccines for all at risk dogs. Some doctors recommend that IN Bb vaccines be given every six months to dogs with extensive dog to dog contact, but I think that’s overkill. For dogs that truly resent having a few drops of liquid squirted into their noses, there is an injectable and a new oral form of Bb vaccine that is also available.

The trick with these respiratory pathogens is to ensure adequate protection without over vaccinating. Check to see if your dog’s injectable combo vaccine contains CAV-2 and Pi. If so, you don’t need those in your intranasal Bb vaccine. My preference is to include CAV-2 in the injectable vaccine (to protect against liver disease; the intranasal vaccine won’t do this), but to use a combination intranasal Bb and Pi product only in those dogs that need it.

Clear as mud?

Dr. Jennifer Coates

Image: Kristof Degreef / Shutterstock