The chilling threat of kennel cough

October 23, 2024

The crisp, autumn air settles in after a long and hot Texas summer, but lurking beneath the excitement is the shadowy threat of the canine infectious respiratory disease complex, otherwise known as kennel cough. Cooler temperatures mean an increase in outbreaks as dogs spend more time indoors in close quarters and their immune systems weaken. Kennel cough is a highly contagious respiratory disease that causes inflammation in the trachea and the bronchi. The complex is a combination of infectious viral and bacterial agents posing a haunting health risk for dogs.

Catherine Campbell, DVM, veterinary diagnostician at the Texas A&M Veterinary Medical Diagnostic Laboratory, TVMDL, in College Station, said an outbreak of this complex can be detrimental to boarding facilities, shelters, or even dog parks. 

“Most of these infectious agents tend to spread via aerosol droplets or even fomite transmission,” Campbell said. “Thus, a high rate of spread within a kennel situation and thus we get the term kennel cough.”

The viruses associated with kennel cough include distemper, parainfluenza, canine influenza and herpes. In addition to Bordetella bronchiseptica, other bacteria like Mycoplasma cynos and Streptococcus equi subspecies Zooepidemicus can also be potential instigators of kennel cough.

How does kennel cough spread in dog communities?

Kennel cough can be prevalent in shelters and kennels because dogs are often housed in close proximity, which facilitates easy transmission of pathogens.

Kennel cough can be easily transmitted through:

  • Direct contact (e.g., licking or nuzzling)
  • Breathing in cough or sneeze droplets from infected dogs
  • Exposure to droplet-contaminated items (e.g., toys, bedding, or water bowls)

Healthy dogs that catch kennel cough usually recover fully after about three weeks, however, some dogs might be more susceptible to serious conditions associated with the complex.

For example, puppies are more vulnerable to critical effects because of their immature immune systems. Some might not have certain vaccinations as there are age restrictions for some administration.

Inversely, older dogs also experience health risks as some have a decreased immune defense. Additional complications like heart failure, diabetes or cancer may also increase a dog’s susceptibility to the complex.

Canine owners should also keep a close eye on pregnant dogs and quickly recognize unusual behavior.

Clinical signs of kennel cough

A main indicator of kennel cough is a persistent, dry cough, which some experts have described as sounding like a “goose honk.”

Other signs include:

  • Sneezing
  • Runny nose
  • Watery eyes or eye discharge
  • Loss in appetite
  • Less energy

Campbell said that it is important to identify the etiological agent early in the disease process as several diseases can present with similar clinical signs. For example, canine distemper virus has similar respiratory signs to other viral agents, but can lead to more concerning health risks. Therefore, knowing the etiological agent is critical in providing effective treatment.

Testing options at TVMDL

TVMDL’s molecular diagnostics section offers a multiplex real time PCR panel that detects seven of the most common canine respiratory pathogens. TVMDL also has a Mycoplasma species gel-based PCR test that detects general Mycoplasma species.

Assistant Molecular Diagnostics Section Head, Megan Schroeder, PhD, said fresh lung tissue or nasal, tracheal, or pharyngeal swabs are the most efficient in detecting respiratory pathogens.

“The preferred swab sample is a plastic Dacron swab, as opposed to a cotton tip wooden swab,” Schroeder said. “Those cotton tipped wooden swabs are processed with some chemicals that can be inhibitory to PCR.” 

Additionally, clients should avoid the use of culture swabs when submitting samples for the PCR test. These types of swabs contain a gel at the bottom of the container that holds the swab. The substance helps the process of culturing bacterial pathogens, but Schroeder warned it can inhibit PCR testing. Therefore, if clients use a culture swab, they should place the swab inside a separate container and not the packaged container holding the gel. All swabs should be shipped in a clean, sterile tube with a few drops of saline to prevent the sample from drying out during transport.

“I recommend early diagnostic testing and intervention,” Campbell said. “That really helps in setting expectations and getting a handle on these highly infectious agents and shutting down the spread.”

For more information on canine respiratory disease testing options, call the College Station lab at 1.888.646.5623 or the Canyon lab at 1.888.646.5624 or visit tvmdl.tamu.edu.

Maci Guay

Communications Student Writer
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