Infectious tracheobronchitis (Kennel Cough) is generally a mild self-limiting disease involving the trachea and bronchi of any age dog. It spreads rapidly in high stress, closely confined conditions such as hospitals or kennels. It is usually caused by a virus, primarily Canine adenovirus 2, canine parainfluenza virus or canine distemper virus. Canine hepatitis virus, canine reoviruses types 1,2 and 3 and canine herpesvirus also have been implied to be causative agents.
The virus damages the respiratory lining and paves the way for secondary bacterial invaders. Bordetella bronchiseptica is the principal bacterial invader. Hence there has been a vaccine developed with live avirulent culture of B. bronchiseptica to give intranasally. Injectable forms of inactivated whole bacterial cultures or extracts have been made but are not always available due to problems with local or systemic reactions. I recommended to clients the intranasal product whenever possible. However you must remember you are only protecting against one relatively harmless bacteria.
Once the virus does its damage, a whole slew of different bacteria can come in and cause significant illness. Considering what is in the dog's environment or what it is exposed to will determine what types of bacteria could become secondary invaders. You could see both gram positive and gram negative types of bacteria. The cases under discussion have been caused by Streptococcal bacteria, which is a common inhabitant on dogs and people but under the right conditions can cause harmful disease. Also Streptococcal infections are often food related.
The best recommendation is to discuss with your veterinarian what types of Distemper combo vaccine is best for your dogs depending on what area of the country you are in and to keep them well vaccinated. Some people also recommend the Bordetella vaccine - it won't protect your dog for all bacteria he/she might be exposed to, but it will protect against one of the most commonly isolated pathogens. Secondly, keep stress to a minimum and good health to a maximum!! Consistent exercise and a clean environment are the only way to beat disease. The JRT's have little to worry about (yet) since most of our shows are out in the open with good ventilation and they are not overly crowded or dirty.
Previous taken from an email sent by K. Wilson, DVM