Kennel cough basics

Infectious Tracheobronchitis, commonly known as kennel cough, is a bronchitis illness characterized by a harsh, hacking cough. Most people say the cough sounds as though their dog has something stuck in his throat.

Kennel cough is similar to a chest cold in humans and will generally resolve itself on its own with no medications necessary. Under certain circumstances, however, it can be deadly, and requires effective treatment. Here are the basics on the condition, and how to know when to seek help.

How do dogs become infected with kennel cough?

The respiratory tract of a normal, healthy dog has substantial safeguards against invading infectious agents.
The most important safeguard is called the mucociliary escalator. The escalator is made up of tiny, hair like structures, called cilia, which protrude from the cells lining the respiratory tract.

There is a coat of mucus over the hairs and this mucous traps debris, including infectious agents, and the cilia move the mucus and the trapped debris up to the throat where it is either coughed up and/or swallowed.

The mucociliary escalator can be damaged by:

  • Stress from being shipped
  • Stress from overcrowding
  • Exposure to heavy dust
  • Exposure to cigarette smoke
  • Infectious viral agents such as reovirus, adenovirus, parainfluenza, and distemper
  • Prolonged exposure to cold temperatures
  • Poor ventilation

Without the mucociliary escalator, invading bacteria can simply invade the dog’s airways unimpeded.

A bacterium called Bordetella bronchiseptica can cause much distress in dogs because it has defenses against the mucociliary escalator:

  • Within three hours of contact, it can attach to the cilia, leaving them unable to move.
  • It then secretes a substance that disables the immune cells that normally consume and destroy bacteria.

Since Bordetella usually invades the dog’s body with another bacteria or virus such as the ones mentioned above, kennel cough is actually the result of multiple attacks rather than by one agent.

Most dogs are infected when they are contained in a hot, crowded area that receives poor air circulation but lots of warm air, such as a boarding kennel, obedience class, an animal shelter or hospital, or a grooming parlor. Most acute coughing in dogs is due to infection and usually is some form of kennel cough.

How contagious is kennel cough?

Bordetella infection is not contagious to humans (although it is similar to whooping cough), but it can be passed through many animals. It is particularly contagious among dogs who are stressed, have not had vaccinations against it, and have been exposed to other minor viruses.

Dogs should be kept current on their Bordetella vaccinations because you cannot always be sure when they might be placed in a situation that exposes them to the virus.

How is kennel cough treated?

Most cases of kennel cough go away on their own, but some doctors will prescribe antibiotics in hopes of killing the Bordetella organism. You can also give the infected dog vet-approved cough suppressants to provide comfort while he battles the illness. Your veterinarian may prescribe a combination of antibiotics and cough suppressants for optimal comfort and recovery time.

When is kennel cough considered a serious condition?

It can be very serious for young puppies, especially if they have been shipped recently, such as pet store puppies. They are especially prone to severe cases of infectious bronchitis that frequently progress to pneumonia. Moreover, since the virus incubates for two to twelve days, an owner may suddenly find himself with a very sick puppy.

If a dog that has the distemper virus is exposed to Bordetella the potential for serious problems is extremely high.

Vaccination options

There are two options for kennel cough vaccination:
An injection is the method of choice for aggressive dogs, who may try to bite if their muzzle is restrained. Injections provide good systemic immunity if dogs are given two doses after they are four months old and receive an annual booster. It’s possible that an injected vaccination may only lead to less severe infection, rather than complete prevention of infection.

Intranasal vaccination can be administered to puppies as young as two weeks, with immunity generally lasting for ten to twelve months. Typically, your dog should receive a booster dose annually. The advantage of the intranasal vaccination is that immunity is stimulated in the nasal passages, right where the natural infection tries to take hold.

Intranasal vaccination needs four days to become effective, so try to anticipate when your dog may be exposed and vaccinate accordingly. Some dogs will sneeze or have some nasal discharge for up to a week after the intranasal vaccination. Usually the nasal vaccination provides faster immunity than the injected vaccination.

If your dog is already incubating kennel cough, the vaccination is useless.

My dog’s been infected. What if the symptoms aren’t improving?

While kennel cough usually clears up on its own, there should be partial relief after one week of treatment. If there is no improvement, consult your veterinarian about bringing your dog in for a re-check. He may advise doing chest x-rays at this time.

Source: Adapted from Veterinary Information Network