Canine parainfluenza virus causes acute upper respiratory disease, which is usually mild. Co-infection with other viruses (canine adenovirus type 2, canine herpesvirus...) or bacteria (especially Bordetella bronchiseptica) results in a more severe disease - canine infectious tracheobronchitis or "kennel cough". The main clinical signs are a severe paroxysmal cough with retching and vomiting, and discharge from the eyes and nose.
