Infectious Tracheobronchitis of Dogs (Kennel cough)
Introduction: Infectious tracheobronchitis results from inflammation of the upper airways.
Generally, it is a mild, self-limiting disease but may progress to fatal bronchopneumonia in puppies or to chronic bronchitis in debilitated adult or aged dogs.
The illness spreads rapidly among susceptible dogs housed in close confinement including veterinary hospitals and kennels.
Etiology: What we call "kennel cough" may be due multiple organisms... any combination of which may be the cause of the throat irritation causing a hoarse throat and long lasting cough. Having so many possible causes may be one reason the kennel cough vaccine we have available doesn't always work so well.
Canine parainfluenza virus, canine adenovirus 2 (CAV-2), or canine distemper virus can be the primary or sole pathogen involved.
Canine reoviruses (types 1, 2, and 3), canine herpesvirus, and canine adenovirus 1 (CAV-1) are of questionable significance in this syndrome.
Bordetella bronchiseptica may act as a primary pathogen, especially in dogs less than 6 months old; however, it
and other bacteria (usually gram-negative organisms such as Pseudomonas sp, Escherichia coli, and Klebsiella pneumoniae) may cause secondary infections after viral injury to the respiratory tract.
Concurrent infections with several of these agents are common.
The role of Mycoplasma sp has not been clearly established.
Stress and extremes of ventilation, temperature, and humidity apparently increase susceptibility to, and severity of, the disease.
Clinical Findings and Diagnosis: The prominent clinical sign is paroxysms of a harsh, dry cough, which may be followed by retching and gagging.
The cough is easily induced by gentle palpation of the larynx or trachea.
Affected dogs demonstrate few if any additional clinical signs except for partial anorexia.
Body temperature and WBC counts usually remain normal.
Development of more severe signs, including fever, purulent nasal discharge, depression, anorexia, and a productive cough, especially in puppies, indicates a complicating systemic infection such as distemper or bronchopneumonia.
Stress, particularly due to adverse environmental conditions and improper nutrition, may contribute to a relapse during convalescence.
Tracheobronchitis should be suspected whenever the characteristic cough suddenly develops 5-10 days after exposure to other susceptible or affected dogs.
Usually severity diminishes during the first 5 days, but the disease persists for 10-20 days. Tracheal trauma secondary to intubation may produce a similar but generally less severe syndrome.
Treatment:
Preferably, affected dogs should not be hospitalized because the disease is usually highly contagious (and also self-limiting).
Appropriate management practices, including good nutrition, hygiene, and nursing care, as well as correction of predisposing environmental factors, hasten recovery.
Treatment at our clinic consists of:
Doxycycline antibiotics to fight and prevent secondary bacterial infections.
Cough suppressants, cough syrups, and products to soothe the throat.
Time; symptoms can last several weeks.
Prevention:
Several brands of vaccines are available that give moderately successful prevention or at least reduce the severity of the disease.
The success of all the available vaccines are limited but still worth giving and recommended... often required ... prior to boarding in commercial kennels, dog shows and so forth where the risk of exposure to the disease is common.
The vaccine works best if given several weeks prior to exposure.
Duration of protection from the vaccine starts to wane after about 6 months.
