Kennel cough, known in veterinary circles as infectious tracheobronchitis, is a group of highly contagious, acute upper-respiratory tract diseases of dogs that commonly involve inflammation of the larynx (laryngitis), trachea (tracheitis) and bronchii (bronchitis). It was given its common name because it spreads rapidly among dogs that have been at boarding kennels or other places where large numbers of dogs congregate in close proximity.
Causes of Kennel Cough
Kennel cough can be caused by one or a combination of several different bacterial, viral or mycoplasmal agents. In most cases, the condition occurs when a dog becomes infected with the canine parainfluenza virus and/or the Bordetella bronchiseptica bacteria. Canine adenovirus types CAV-I and CAV-2, along with canine herpesvirus, canine distemper virus and mycoplasma, can also cause kennel cough. Secondary bacterial infections, including bronchopneumonia, can occur when a dog becomes infected with another respiratory pathogen. These secondary infections can be quite serious.
Preventing Kennel Cough
The clinical manifestations of kennel cough typically show up within a week or so of exposure to infected animals. Prevention is best accomplished by keeping healthy dogs away from dogs that are or may be infected. The most common at-risk areas are boarding kennels, animal shelters, commercial pet shops, research facilities, grooming facilities, dog shows, agility trials, field trials, dog parks, dog groomers, veterinary clinics and similar close-contact environments. Several vaccines are commercially available for canine kennel cough, some of which are part of broader, combination canine vaccines. The intranasal Bordetella vaccine is highly recommended for at risk dogs; it should be given twice yearly to ensure its effectiveness. An intramuscular Bordetella vaccine is also available, as are vaccines for canine parainfluenza virus and adenovirus types CAV-1 and CAV-2.
It is possible for immunocompromised people to become infected by Bordetella bronchiseptica, although this is uncommon.
Infectious canine tracheobronchitis, more commonly known as kennel cough, is a highly contagious, acute upper-respiratory tract disease complex that occurs in dogs. Fortunately, the signs of kennel cough are easy to recognize. If a dog exhibits these signs, particularly if it has recently been boarded, to a dog show, to the dog park or otherwise exposed to a number of dogs in close quarters, the dog's owner should take it to the veterinarian as soon as possible.
Symptoms of Kennel Cough
Most dogs with kennel cough show a classic course of mild disease characterized by one or more of the following signs:
Sudden onset of a deep, dry, harsh, hacking cough, without any other signs of illness or discomfort
A cough that sounds like the dog has "something stuck in its throat" or is choking
An unproductive cough
Fits of coughing, especially after exercise
Gagging, especially after coughing or exercise
Retching, especially after coughing; frequently accompanied by a white, foamy mucus
Possible change in the dog's bark
Dog is bright, alert and responsive
Dog has a good appetite
The signs of kennel cough normally appear about 4 to 7 days after exposure to an infected dog, which usually occurs in a high dog-density boarding or other situation, where dogs congregate in what might be less than ideal sanitary or hygienic conditions. Otherwise, most dogs with kennel cough are clinically normal.
In some cases, and more so in puppies or unvaccinated adult dogs, kennel cough can progress to involve more severe secondary respiratory tract infections that include bronchopneumonia and rhinitis. When a dog with kennel cough develops secondary bacterial infections, it may develop one or more of the following symptoms:
Fever (usually low grade and fluctuating)
Nasal discharge (runny nose)
Ocular discharge (runny eyes)
Deep, moist, productive cough
Difficulty breathing (respiratory distress; dyspnea)
Decreased appetite (inappetance; anorexia)
While the symptoms of uncomplicated kennel cough may not seem particularly serious, the infection is highly contagious and therefore should be treated immediately.
Dogs at Increased Risk
Dogs of any age are at risk of developing kennel cough, but puppies from 6 weeks to 6 months of age, and unvaccinated or adults with compromised or weakened immune systems, tend to be more frequently and more severely affected. Puppies acquired from commercial pet shops or so-called "puppy mills", and those coming from shelters, are also more likely to develop kennel cough. There is no gender or breed predisposition to developing kennel cough.
Kennel cough (infectious canine tracheobronchitis) is a fairly common, acute and highly contagious upper respiratory tract infection that typically is transmitted in areas where large numbers of dogs congregate in close quarters. It is not particularly difficult to diagnose.
How Kennel Cough is Diagnosed
When a dog presents with a dry, hacking cough but otherwise appears and acts normal, most veterinarians will have a high degree of suspicion of kennel cough, especially if the dog has recently been at a boarding kennel or some other place frequented by many dogs. The initial database typically includes a thorough physical examination and history and a complete blood count, serum chemistry panel and urinalysis. The results of these tests can be suggestive of tracheobronchitis and can also identify other related or unrelated abnormalities. Thoracic radiographs (chest x-rays) can help to rule out non-infectious causes of coughing, and can also identify more severe secondary respiratory tract infections such as pneumonia.
Advanced diagnostic testing may include a transtracheal wash or a bronchoalveolar lavage. These procedures essentially involve flushing the upper respiratory tract with sterile fluid and retrieving that fluid for microscopic examination, to identify infectious bacterial, viral and/or micoplasmal organisms. Culture and sensitivity testing on samples containing bacteria is very helpful in formulating an effective treatment plan.
Because kennel cough is so contagious, most veterinarians recommend that uncomplicated cases be treated and managed at home. Patients with pneumonia or other secondary infections or complications probably should be isolated and treated on an inpatient basis.
Most cases of kennel cough are mild, and most dogs recover from the illness in a short period of time.
Treatment Options for Kennel Cough
The best treatment for dogs with kennel cough is rest in a quiet, stress-free environment. Typically, their appetite is unaffected, and they should continue to eat their normal diet with free access to fresh water at all times. Young puppies can have mild to severe nasal congestion and may require more intensive treatment to loosen nasal secretions and ease breathing. When secondary bacterial pneumonia accompanies kennel cough, the dog may require hospitalization.
All cases of kennel cough should be managed by a veterinarian. Affected dogs should be kept away from other dogs so that they do not spread the disease. They should be housed indoors in a clean, warm, dry, well-ventilated and quiet environment. In many cases, a humidifier or vaporizer are helpful to reduce congestion; bringing the dog into the bathroom while the owner showers can be beneficial as well. Moderate exercise can help stimulate nasal and bronchial drainage, but strenuous activity should be avoided.
In addition to supportive care, antibiotics are commonly prescribed for dogs with kennel cough, especially if secondary infections develop. Cough suppressants can also help control bothersome coughing.
The prognosis for dogs with simple kennel cough is very good to excellent. Dogs with uncomplicated kennel cough typically recover even without treatment in about 10 to 14 days. Puppies or unvaccinated older dogs have a more guarded prognosis due to their immunocompromised status and increased risk of developing bronchopneumonia. Severe kennel cough with secondary infection may have a typical course ranging from 2 to 6 weeks. However, without treatment, they can die from complications involving multiple lung lobes.