Kennel cough or tracheobronchitis is a highly contagious canine illness characterize by inflammation of the upper respiratory system. It can be caused by viral infections such as canine distemper, canine adenovirus, canine parainfluenza virus, or canine respiratory coronavirus, or bacterial infections such as Bordetella bronchiseptica. It is so named because the infection can spread quickly among dogs, such as in the close quarters of a kennel.