When Fiona Anderson brought her 11-year-old petite mini Goldendoodle, Basil, in for a routine dental cleaning, she had no idea anything was wrong.

A sweet, cuddly dog who loves his daily walks, Basil showed zero symptoms of illness. But as the vet listened to his chest before the procedure, they picked up a heart murmur.

For many families, like Basil’s, that subtle sound is the first hint of Stage B2 mitral valve disease—a condition where the heart is working harder and beginning to enlarge, quietly progressing toward congestive heart failure. The diagnosis often brings a wave of anxiety, expensive ultrasounds, and uncertain monitoring.

But a new study that pairs a simple 60-second breath test with a lifesaving medication offers a ray of hope. Matthew Tanner, a cardiology resident at the University of Minnesota College of Veterinary Medicine (CVM), leads the study.

By slipping a small mask over a dog’s snout for just one minute, he captures a sample of exhaled air, and the patient’s job is done. Enrolled dogs like Basil leave with three months of free cardiac medication, a fully funded follow-up visit, and the chance to pioneer a gentler, faster way to monitor heart health. "He's always a happy boy when he comes out, and he's happy to keep going back," Anderson says.

This research marks the exciting next chapter of a previous study led by CVM cardiologist Christopher Stauthammer, in partnership with local startup VOCxi, to detect heart disease through volatile organic compounds in a dog’s breath. Now, the project is moving from basic detection to active treatment tracking to explore how the breath test can be used to optimize medication choices—and our pets’ long-term prognoses.

"This research gives us the chance to take the next step forward in cardiac medicine and give families more time with their pets," notes Tanner.

From breath prints to better treatment

Tanner’s research focuses on dogs newly diagnosed with Stage B2 heart enlargement who haven’t yet entered active heart failure. These patients are prescribed pimobendan (Vetmedin), a vital drug that helps the heart pump more effectively and delays the onset of congestive heart failure by an average of 15 months—giving owners more than a year of extra belly rubs, walks, and quality time. While the medication is widely known to help, clinicians currently rely on costly heart ultrasounds, which can range from $700 to $1,200 per visit, to see if a patient is responding.

To find a simpler alternative, Tanner’s trial measures a dog’s "breath print" before starting pimobendan and again three months later. Basil recently completed his three-month follow-up breath test after starting on pimobendan, and the team will be able to use the new data to see what’s changed. By analyzing shifts in exhaled chemical compounds, his team hopes to determine whether a dog’s breath signature shifts back toward normal as heart function improves, or if subtle VOC changes can spot non-responders whose disease is quietly progressing before physical symptoms ever appear.

If successful, this breathalyzer technology could transform how heart disease is managed in family veterinary practices. For pet owners, it promises an affordable, non-invasive alternative to repeated, expensive ultrasounds. For general practitioners, the test offers much-needed clarity—helping them quickly distinguish whether a coughing dog is in heart failure or simply dealing with an airway issue like bronchitis, thereby avoiding unnecessary prescriptions. Ultimately, these exhaled signatures give primary care clinicians the targeted diagnostic confidence they need to start secondary cardiac medications at the ideal moment.

Advancing care through research

While Tanner’s focus is on canine hearts, exhaled breath analysis is opening doors across medicine. Similar breath technology is being explored in human medicine to monitor heart failure and screen for early-stage cancers. And researchers are even investigating whether breathalyzers could help emergency vets quickly identify accidental toxicities, such as THC ingestion.

"Analyzing compounds in breath is in its infancy in veterinary medicine, but the potential is massive," Tanner reflects.

For Anderson, a pediatric neuropsychologist and former U of M researcher herself, enrolling Basil in the study was an easy decision.

"This is how we develop new treatments," Anderson says. "By Basil being part of this study, hopefully we can find an even less invasive way to diagnose and manage various problems in dogs. Without this kind of research, treatments don't advance—they don't get any better."

Anderson also highlighted the value of academic veterinary centers like CVM: "This is where the cutting-edge work is happening. You get to work with a combination of a student who's fresh out of school with all the new knowledge, and a senior person who's a leading researcher with lots of experience. They're all working together with your pet."