'Kennel Cough' is the term that was commonly applied to the most prevalent upper respiratoryproblem in dogs in the United States. Recently, the condition has become known astracheobronchitis, canine infectious tracheobronchitis, Bordetellosis, or Bordetella. It is highly contagious in dogs. The disease is found worldwide and will infect a very high percentage of dogs in their lifetime.Infectious agents involved
There are many different agents that can cause of tracheobronchitis. The most common are parainfluenza virus, Bordetella bronchiseptica, and mycoplasma. Canine adenovirus type 2, reovirus, and canine herpes virus are thought to possibly contribute to the disease, as well. Although any one of these organisms can cause symptoms of the disease, the majority of cases are the result of more than one organism.
The most common viral agent is parainfluenza virus. This common virus will cause mild symptoms lasting less than 6 days unless there is involvement of other bacteria, as is usually the case. Most 5-way vaccines and 'kennel cough' vaccines offer some protection against this virus.
Bordetella bronchiseptica is the most common bacteria isolated from dogs with tracheobronchitis. Clinical signs of infections occur 2-14 days after exposure, and if uncomplicated with other agents, symptoms will last around 10 days. However, after the infection has been resolved, the affected animal will continue to shed the bacteria for 6 to 14 weeks and can spread the disease to other susceptible animals during that time. Bordetella is one of the agents protected against through the use of intranasal 'kennel cough' vaccines. Parainfluenza and Bordetella most commonly appear together in infectious tracheobronchitis, creating a disease that normally lasts from 14-20 days.
The most common symptom is a dry hacking cough sometimes followed by retching. Many owners describe the cough as having a 'honking sound.' A watery nasal discharge may also be present. With mild cases, dogs continue to eat and be alert and active. Many times, there is a recent history of boarding or coming in contact with other dogs. In more severe cases, the symptoms may progress and include lethargy, fever, inappetence, pneumonia, and in very severe cases, even death. The majority of severe cases occur in immunocompromised animals, or young unvaccinated puppies.
Diagnosis is usually based on the symptoms and a history of recent exposure to other dogs. Bacterial cultures, viral isolation, and blood work can be performed to verify individual agents of the disease, but due to the characteristic nature of the symptoms, these tests are not routinely performed.
There are two treatment options depending on the severity of the disease. In the most common mild (uncomplicated) form of the disease, antibiotics may or may not be used. Treating the mild case does not shorten the length in which the animal will be a potential spreader of the disease. In addition, bronchodilators like aminophylline or cough suppressants may also be used in treatment of mild cases.
In more severe (complicated) cases where the animal is not eating, running a fever, or showing signs of pneumonia, antibiotics are often used. The most common ones are doxycycline ortrimethoprim-sulfa. However, many other choices are also available. Steroids or cough suppressants are not usually recommended because of the risk of immunosuppressionwith steroids and the need to continue to clear extra fluid or mucous in pneumonia patients. Bronchodilators and even aerosol therapy can be used. In moderate or severe cases, veterinary care should be instituted, as the resultant pneumonia could become life threatening if not treated properly and promptly.
Because pressure on the throat and trachea can make coughing worse, it is recommended that dogs with a cough should wear a head collar or harness instead of a regular neck collar.
Vaccination and prevention
The best prevention is to not expose your dog to other dogs, especially young puppies. If this cannot be avoided, then proper vaccination is the next best option. Chances are that if your dog is regularly vaccinated with a standard 5-way or 7-way vaccine, he is already being protected against several of the agents causing tracheobronchitis, mainly parainfluenza and adenovirus. However, these vaccines alone rarely provide protection against contracting the disease, although they will help reduce the severity of the disease if the animal becomes infected.
There is an injectable Bordatella vaccine, and one that is given intranasally (squirted into the nostrils). Neither vaccine will totally prevent infection with Bordatella. For the injectable vaccine, 2 doses must be given 3-4 weeks apart, and protection does not occur until 1-2 weeks after the second injection.
In kennels where tracheobronchitis is a problem, strict hygiene with thorough cleaning and disinfection of cages and food and water containers is essential. In addition, kennels that are indoors should have good ventilation with an air turnover rate of at least 12 times an hour. Agents causing tracheobronchitis can be transmitted on hands and clothing as well as through the air, so infected animals must be isolated and handlers should wear gloves and use proper handwashing to help prevent spread. Vaccination of all animals, especially puppies is indicated in problem kennels. After initial vaccination as puppies, a yearly booster is recommended. However, some dogs that are at very high risk are vaccinated every six months.