Canine respiratory illness cases down across Colorado; CSU continues to investigate fall spike

Contact for reporters:
Jennifer Dimas
jennifer.dimas@colostate.edu
970-988-4265

Reports of canine respiratory disease in Colorado have dropped from peak case numbers last year, according to Colorado State University veterinary experts. CSU researchers, however, are still investigating the potential origins of the fall spike.

“The great news is that the number of cases being reported in Colorado has been dropping since our suspected peaks between August and December,” said Dr. Michael Lappin, an internal medicine specialist and director of the Center for Companion Animal Studies at CSU. “Why that trend is occurring is unknown but may be related to our pets spending less time in social situations that might include ill dogs during the winter months.”

Last year’s wave of canine respiratory disease differed from previous versions. Dogs experienced prolonged coughs, up to several weeks, and more cases developed what appeared to be secondary pneumonia. In September, October and November, CSU’s Veterinary Teaching Hospital saw more than double the cases of canine pneumonia compared with the same period in 2022. Cases also spiked elsewhere, including Oregon, California, Florida and New Hampshire, as well parts of Canada.

In Colorado, CSU experts have been working with partners across the state on multiple fronts to investigate the origin of last year’s elevated numbers, Lappin said. Those efforts have included examining whether any of the previous spikes were the result of one of the 10 viruses or bacteria already known to cause canine respiratory disease, if any of those pathogens have changed or if there are any new causes.

“One of our first responses was to work with the state of Colorado to identify areas that seemingly had high numbers of cases to provide free diagnostic testing,” Lappin said.

CSU researchers in the Veterinary Diagnostic Laboratory and the Center for Companion Animal Studies partnered with clinics in Fort Collins, Denver, Colorado Springs and Grand Junction to test samples. This work will continue throughout February, and CSU will release results when that activity is completed.

Separately, Dr. Blaire MacNeill, a clinical microbiology resident at CSU, led a medical records review of 87 cases of suspected infectious respiratory disease from the Veterinary Teaching Hospital between Sept. 1 and Jan. 18. The majority of cases entered the hospital through the urgent care department. That review, however, revealed no obvious patterns of organisms previously recognized to cause infectious respiratory disease. Four of the cases were fatal, one of which involved a dog that had another pre-existing condition.

Pet owners, Lappin said, should continue to follow previously released guidelines, which include keeping dogs up to date on vaccinations and watching them closely if they develop a cough. Exercise caution regarding nose-to-nose contact with unfamiliar dogs, as their medical history and exposure risks may be unknown, and when choosing pet care services, ensure transparency by inquiring about protocols for isolating sick dogs and rigorous cleaning practices. This commitment to best practices underscores the facility’s dedication to pet health and safety.

For more information, pet owners can view a live webinar on this topic on Feb. 13 at noon. Dr. Lappin will participate in a panel discussion on the current state of canine respiratory illness hosted by Trupanion, a company that provides pet insurance for dogs and cats.

Statewide testing was funded in part by Zoetis Animal Health.