Kennel cough is caused by damage to the tracheal lining from infectious agents like bacteria or viruses. Dogs with a weakened immune system are prone to get the infection more frequently than those who have a stronger immunity.
A dog can become immune to certain strains of the virus or bacteria accidentally. This occurs when they are exposed to a limited level of a virus or bacteria that helps them resist infections. The result is that such dogs can remain healthy, even when they are in close quarters with dogs infected with the kennel cough virus.
However, immunity against kennel cough can be obtained in a planned manner, as well. Kennel cough in dogs is transmitted like a common head cold in humans. The causative agents can be present in the air expelled by an infected dog, which are carried in the microscopic water vapors or dust particles present in the air. Although the damage to the tracheal lining is superficial, nerve endings get exposed, and inhaled air causes irritation-- which leads to persistent cough. Infected dogs start showing signs of dry, hacking cough three to seven days after the initial infection.
The duration of kennel cough in dogs is one to three weeks. Most dogs are able to recover without any medication. However, three weeks can be a harrowing experience for the dog and the owners. An infected dog is likely to cough all the time, with coughing bouts lasting for minutes at a time.
The standard 5-way or 7-way vaccine normally provides sufficient protection against the parainfluenza virus and adenovirus, the two most common viral agents that cause kennel cough in dogs. Even if you are not planning to board your dog, exposure to the virus can occur from dog shows or being around an infected dog in the neighborhood. A species-specific diet and natural remedies for strengthening immunity can provide additional protection.
A localized intranasal vaccine is also available. This vaccine is for specific protection against parainfluenza and Bordetella bronchiseptica, the bacterium responsible for bacterial infection that leads to kennel cough in canines.
Dogs may show signs similar to kennel cough for some time after vaccination, which disappear without treatment. A vaccinated dog may continue to shed the virus for three days, which makes other dogs more vulnerable to infection. Therefore, this vaccine should be used with care, and is generally advised for dogs that are at a higher risk of contacting infection.
Kennel cough is not considered to be a risk for humans. It may, however, cause disease in some people, especially young children and adults with a weak immune system.