Causative Agent: Canine parainfluenza virus (CPiV) is a member of the Paramyxovirus family, along with the viruses which cause canine distemper, human measles, and mumps. This virus is found all over the world.

Clinical Signs: CPiV is most commonly associated with upper respiratory tract illness, and is one of the most common viruses isolated from dogs with kennel cough (infectious tracheobronchitis). Damage to the delicate tissues of the upper respiratory tract by CPiV allows secondary infections to occur, most notably with bacteria such as Bordetella bronchiseptica, Pasteurella species, or Streptococcus species. Infection with CPiV is usually associated with upper respiratory tract symptoms such as coughing, nose or eye discharge, and sneezing. Under experimental conditions, CPiV has also been found to cause inflammation and swelling of the brain in puppies, although it is debatable whether or not this actually occurs under natural circumstances.

Disease Transmission: Transmission is usually through airborne respiratory secretions (coughing or sneezing) from an infected dog. Infections can also occur through direct "nose-to-nose" contact or through contaminated hands, dishes, or other equipment. Exposure to other dogs in a kennel or boarding setting is one common source of infection. See the picture on page F102 for an example of a proper kennel.

Diagnosis: Although this procedure is not commonly performed, CPiV can be isolated and identified by taking swabs of the tissues of the nose, pharynx, or trachea of infected dogs. Diagnosis is usually based on history, symptoms, and physical examination.

Treatment: There is no specific treatment available for CPiV infection. The best approach for animals with CPiV involves fluids, supportive care, and antibiotics for secondary bacterial infections.

Prevention: Vaccines are available for parainfluenza in both injectable and intranasal types. Vaccination programs for CPiV should also include vaccination against Bordetella bronchiseptica, canine distemper, and the adenoviruses. These are all viruses/bacteria that have the potential to cause upper respiratory infections. Response to vaccination is usually good and it is generally recommended to booster annually. See the vaccination recommendations on page A905.