Learn the Signs & Sounds of Kennel Cough

American Veterinarian®August 2016
Volume 1
Issue 2

Kennel cough is usually mild and self-limiting, but sometimes it can cause more severe illness.

If you’ve had a dog with kennel cough, you’ve heard the sound: a dry hack often followed by retching or gagging. Some people describe it as sounding like a cat hacking up a hairball. Kennel cough is usually mild and self-limiting, but sometimes it causes more severe illness.


Kennel cough is the common name for infectious tracheobronchitis, a bacterial or viral infection that produces inflammation of the airways (trachea and bronchi). It is spread through respiratory secretions, and dogs can be exposed either through sneezing or coughing or from contact with contaminated surfaces. Stress and poor hygiene can make dogs more susceptible to infection. Contact with any infected dog can lead to kennel cough, but dogs are most at risk when they are housed together in groups:

  • Animal shelters
  • Boarding kennels
  • Dog day care facilities
  • Dog training facilities1,2,3


Most cases of kennel cough are not serious, although the cough can sound a bit alarming. Symptoms of mild kennel cough include the following:

  • Harsh, dry cough
  • Clear, watery discharge from the nose
  • Normal or slightly reduced appetite
  • Normal activity level

The cough usually begins 5 to 10 days after exposure and can last up to 3 weeks.2 In some dogs, especially puppies and those with compromised immune systems, kennel cough progresses to a more severe form. Dogs with complicated kennel cough are at risk of pneumonia or even death. The complicated form produces the following symptoms related to secondary bacterial infection or lung involvement:

  • Moist, productive cough
  • Thick white or yellow discharge from the nose
  • Fever
  • Loss of appetite
  • Reduced activity level1,2


As with the common cold in people, kennel cough can be caused by many different organisms. Mixed infections are likely, especially in dogs with complicated kennel cough. Some dogs are carriers who show no symptoms but can potentially infect other dogs.

The most common cause is Bordetella bronchiseptica. This bacterium is closely related to Bordetella pertussis, which causes whooping cough in humans.4 In one study, Bordetella was found in nearly 80% of dogs with symptoms of respiratory disease and in nearly half of healthy dogs with no symptoms.3

Other bacteria and many viruses can also cause kennel cough or secondary infections associated with it. Some of the viruses involved include the following:

  • Canine parainfluenza virus
  • Canine adenovirus 2
  • Canine distemper virus
  • Canine respiratory coronavirus


Dogs with mild kennel cough may need nothing more than home care, including rest and good nutrition. Contact with other dogs should be limited to keep the disease from spreading.

Depending on the history and clinical signs, your veterinarian might recommend chest x-rays and bloodwork to evaluate the extent of the disease and rule out other causes of coughing. Your veterinarian may prescribe an antibiotic effective against Bordetella or other bacterial infections. (Remember that antibiotics are not effective against viruses.) Cough suppressants are not routinely used, but your veterinarian may suggest one. However, do not give your dog a cough suppressant without consulting your veterinarian. Dogs with complicated kennel cough may require hospitalization.


There are 2 ways to reduce the chance that your dog will get kennel cough: avoidance and vaccination. If you keep your dog away from other dogs by avoiding dog parks, boarding kennels, and so forth, the risk of transmission will naturally be lower.

Vaccination does not always prevent the disease entirely because so many different organisms can be involved, but it usually reduces the severity of symptoms. Vaccines against canine distemper virus and adenovirus 2 are core vaccines that the American Animal Hospital Association recommends for all dogs. Vaccines against Bordetella and canine parainfluenza virus are recommended for dogs that may be exposed to infection.5 Discuss your dog’s exposure risk and vaccine schedule with your veterinarian.



Contact your veterinarian if your dog has a persistent cough. A wide variety of conditions, too many to list in full here, can cause coughing:

  • Tracheal collapse
  • Reverse sneeze (not a true cough)
  • Respiratory irritants
  • Heartworm disease
  • Pneumonia
  • Other infections (bacterial, viral, fungal, or parasitic)
  • Foreign object in the throat
  • Heart disease
  • Cancer


Transmission to humans is rare but possible. Bordetella bronchiseptica infection has been reported in people with compromised immune systems, such as organ transplant recipients and cancer patients. Infection in humans can cause serious disease or no symptoms at all.6


Bordetella bronchiseptica can indeed infect cats, although this is not common. As with other species, cats carrying Bordetella may or may not have any symptoms of respiratory disease. In theory, your cat could actually give kennel cough to your dog.7 However, this is probably more of a concern in animal shelters than in households.

Dr. Laurie Anne Walden received her doctorate in veterinary medicine from North Carolina State University. After an internship in small animal medicine and surgery at Auburn University, she returned to North Carolina, where she has been in small animal primary care practice for over 20 years. Dr. Walden is also a board-certified editor in the life sciences and owner of Walden Medical Writing, LLC.


  • Buonavoglia C, Martella V. Canine respiratory viruses. Vet Res. 2007;38(2):355-373.
  • Tracheobronchitis in small animals. Merck Veterinary Manual website. www.merckvetmanual. com/mvm/respiratory_system/respiratory_diseases_of_small_animals/tracheobronchitis_ in_small_animals.html#v3295117.Revised November 2013. Accessed May 12, 2016.
  • Schulz BS, Kurz S, Weber K, Balzer HJ, Hartmann K. Detection of respiratory viruses and Bordetella bronchiseptica in dogs with acute respiratory tract infections. Vet J. 2014;201(3):365-369. doi: 10.1016/j.tvjl.2014.04.019.
  • Ellis JA. How well do vaccines for Bordetella bronchiseptica work in dogs? A critical review of the literature 1977-2014. Vet J. 2015;204(1):5-16. doi: 10.1016/j.tvjl.2015.02.006.
  • Welborn LV, DeVries JG, Ford R, et al; American Animal Hospital Association (AAHA) Canine Vaccination Task Force. 2011 AAHA canine vaccination guidelines. AAHA website. https:// www.aaha.org/public_documents/professional/ guidelines/caninevaccineguidelines.pdf. Published September/October 2011. Accessed May 12, 2016.
  • Chomel BB. Emerging and re-emerging zoonoses of dogs and cats. Animals (Basel). 2014;4(3):434-445. doi: 10.3390/ani4030434.
  • Foley JE, Rand C, Bannasch MJ, Norris CR, Milan J. Molecular epidemiology of feline bordetellosis in two animal shelters in California, USA. Prev Vet Med. 2002;54(2):141-156.
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