Canine respiratory disease complex arises out of an interaction between an assortment of viral and bacterial pathogens; the
animal's immune response; and a host of environmental factors. No single strategy will be sufficient for prevention, treatment
or control. The good news is we do have many options to reduce the level of environmental contamination and support animals'
ability to ward off infection. When armed with the right tools and information, the impact of this disease can be considerably
lessened. Effective preventive strategies mean fewer dogs become ill, and those few can be more readily isolated and treated
appropriately without putting others at risk.
What causes CIRDC?
It is common to use the term "kennel cough", "infectious tracheobronchitis" and variations on "canine infectious respiratory
disease complex" interchangeably. However, this is an overly simplistic view of a complicated syndrome. Disease is not limited
to the trachea, nor does it always manifest as coughing. Clinical syndromes of CIRDC may include sneezing, nasal and ocular
discharge, and sometimes lower respiratory and/or systemic disease.
Bacterial pathogens implicated in CIRDC include Bordetella bronchiseptica and Mycoplasma spp. Recently, outbreaks of severe infectious respiratory disease associated with Streptococcus zooepidemicus have also been reported. It is likely that secondary bacterial invaders of many species play a significant role in causing
more severe disease in some dogs. Viral pathogens associated with upper respiratory disease in dogs include parainfluenza,
adenovirus, canine respiratory coronavirus (this is distinct from canine enteric coronavirus), and canine herpesvirus. Canine
distemper and canine influenza may also be associated with upper respiratory signs, as well as potentially causing more severe
systemic disease in a proportion of infected dogs. We are still unraveling the complicated etiology of CIRDC, as evidenced
by the fact that several of the pathogens listed above have only been recognized in recent years.
Environmental factors and the animal's immune response play an equally important role in facilitating development of CIRDC.
There's a reason it's called "kennel cough" – several of the pathogens listed above are insufficient in themselves to cause
disease without the additional stress, high contact rate, and other factors associated with kenneling.