2025 Rise in Canine Respiratory Illness Cases in Colorado

A photo of a sad dog, representing the symptoms of dog respiratory illness 2025

In recent weeks, our veterinarians at Sploot Vets have observed a growing number of cases involving canine respiratory illness across Colorado. While this currently is not an official outbreak and has not yet prompted research initiatives, we are monitoring the situation.

The purpose of this article is to educate pet parents on symptoms to watch out for and preventative tips amidst this current rise in canine respiratory illnesses. Read on to learn how to keep your pup safe! 

Is This the Same as the Canine Respiratory Illness Outbreak of Late 2023 to Early 2024?

There is currently no way to determine if the current increase in canine respiratory illness is connected to the mysterious outbreak of late 2023, which affected Colorado (among other states).

Researchers from multiple universities (Colorado State University, University of New Hampshire, Cornell University, Oregon State University) studied the 2023 outbreak, and none found a single/novel causal pathogen. 

Additionally, the seasonal timing of these two surges in canine respiratory illness differs; the 2023 outbreak occurred during autumn. Meanwhile, our veterinarians at Sploot have been noticing a current rise in canine respiratory illnesses since the middle of summer.

Learn more - 2023 Outbreak: Dog Pneumonia in Colorado - What Do We Know?

A Surge in Respiratory Illness in Dogs: What We Are Observing at Sploot Vets 

Across Colorado, we currently have 12 veterinary clinics situated in Denver, Highlands Ranch, and Colorado Springs. In all of our veterinary clinics, we have seen an increase in canine respiratory illnesses over the last few months, particularly since the middle of summer. 

Canine Respiratory Illness: Telltale Symptoms

While this illness can be mistaken for a simple case of kennel cough in dogs (which tends to increase during seasons of increased outdoor activity and dog boarding), the recent respiratory illnesses are (1) presenting with more severe clinical signs, (2) can be resistant to initial first-line antibiotics, and/or (3) progressing to pneumonia.

Here are the symptoms that Colorado dog parents need to be aware of:

  • Persistent coughing – sometimes sounding like gagging or retching
  • Sneezing and nasal discharge – cloudy or green/yellow in color
  • Lethargy – less energy or playfulness than usual
  • Loss of appetite – decreased interest in food
  • Difficulty breathing – especially after strenuous exercise
  • Persistence of symptoms – symptoms may resist kennel cough treatments and/or get worse over time.
A photo of a lethargic dog, representing the symptoms of dog respiratory illness 2025

How the Respiratory Illness in Dogs Spreads

Similar to the 2023 outbreak of dog pneumonia and respiratory illness, we cannot determine the definite mode of transmission while the causal pathogen(s) is not yet identified. 

Based on the cases our veterinarians have handled, however, we see a pattern. Most of the dogs that had a sudden onset of respiratory symptoms were recently taken to any of the following: 

  • Dog parks
  • Daycares or dog boarding facilities
  • Dog grooming salons

This may suggest that the respiratory illness is contracted through close contact and/or via aerosol droplets.

How to Protect Your Dog From Respiratory Illness

Pet parents can take simple but effective steps to reduce risk:

  1. Stay up to date on dog vaccinations (including Bordetella, canine influenza, and distemper/parvo combo) – While the recent respiratory illnesses are not conclusively attributed to any of these, it is essential to recognize that common, transmissible diseases can serve as an entry point for other respiratory illnesses. Therefore, strengthening your pup’s immunity is crucial.
  2. Limit exposure to high-risk areas – especially for senior dogs or those with underlying health concerns
  3. Choose trusted establishments – whether you are taking your dog to a groomer or dog boarding facility, choose establishments that have great hygiene practices and those that only allow entry to dogs with a clean bill of health.
  4. Watch closely for early symptoms – reach out to an urgent care veterinarian promptly to get timely treatment and improve outcomes.

Final Thoughts on Rising Canine Respiratory Illnesses in Colorado

With an increase in respiratory cases among dogs, vigilance is key. Keep an eye on your pup’s health, minimize unnecessary exposure, and seek veterinary care if symptoms develop. Early intervention can help your pet recover faster and prevent complications.

A photo of a dog brought to Sploot Vets, a vet clinic in Colorado to get immunizations that can help prevent the development of dog respiratory illness 2025

Sploot Vets: Your All-in-One Colorado Vet

At Sploot Vets, we provide top-tier, all-in-one vet care with a Fear Free approach, making every visit as stress-free as possible. Whether your pet requires primary care, urgent vet care, or emergency vet services for unexpected illnesses, our team is here to help. 

With vet clinics in Denver, Highlands Ranch, and Colorado Springs, we’re open 365 days a year with extended clinic hours to give your pet the reliable care they deserve.

Call us at (720) 770-8656 for urgent care or schedule an appointment here!