Does Your Dog Have Pulmonic Stenosis?
A narrowed pulmonic valve, exercise intolerance, and a heart working too hard. Here's what pulmonic stenosis looks like.
If your vet just told you your puppy has a heart murmur caused by pulmonic stenosis, it’s okay to feel a little shaken. But here’s the thing: this is one of the most common congenital heart defects in dogs, and many dogs with it live full, happy lives. What matters most right now is understanding what you’re dealing with and knowing what to watch for.
Pulmonic stenosis (also called pulmonary stenosis) is a narrowing around the pulmonic valve, the gateway between the right side of the heart and the lungs. When that opening is too tight, the right ventricle (the heart’s lower-right chamber) has to push much harder to get blood through. Over time, that extra strain is what causes problems. The good news: how much strain depends almost entirely on how severe the narrowing is, and mild cases often need nothing more than routine check-ins.
TL;DR
- Pulmonic stenosis is a congenital heart defect where the pulmonic valve is narrowed, forcing the right ventricle to work harder to pump blood to the lungs.
- Severity determines everything. Mild cases rarely cause symptoms. Severe cases can lead to exercise intolerance, fainting, fluid buildup, and right-sided heart failure.
- An echocardiogram grades the severity and guides treatment, which ranges from monitoring to balloon valvuloplasty.
- Bulldogs, Boxers, Beagles, and several terrier breeds are most commonly affected. Dogs with pulmonic stenosis should not be bred.
- Echocardiograms and valvuloplasty are costly. Enrolling your puppy in pet insurance before any murmur is documented is what keeps coverage on the table.
What causes pulmonic stenosis in dogs?
Pulmonic stenosis is a congenital defect, meaning dogs are born with it. The pulmonic valve forms incorrectly during fetal development, leaving the opening too narrow for normal blood flow. It’s not something that develops from lifestyle or diet.
Some breeds are genetically predisposed. The most commonly affected include:
- Bulldogs, especially English Bulldogs
- Boxers
- Beagles
- West Highland White Terriers, Mastiffs, Samoyeds, and Miniature Schnauzers
Because it’s hereditary in these lines, dogs diagnosed with pulmonic stenosis should not be used for breeding, regardless of how mild the individual dog’s case is.
What are the signs of pulmonic stenosis in dogs?
In mild cases, a heart murmur picked up during a routine exam may be the only sign your dog ever has. Many dogs with low-grade pulmonic stenosis live their entire lives without showing anything more than that.
In moderate to severe cases, the right ventricle is under enough pressure that symptoms start to show:
- Exercise intolerance: tiring quickly on walks or reluctance to play
- Fainting, especially after activity or excitement
- Labored or rapid breathing at rest
- A swollen, rounded abdomen from fluid backup, called ascites
- Weakness or lethargy
Ascites and persistent fatigue are signs the heart is struggling to keep up. If you’re seeing these, your dog needs to see a vet promptly, not at the next available routine appointment.
How do vets diagnose and grade pulmonic stenosis?
The starting point is usually a heart murmur heard through a stethoscope. But a murmur alone doesn’t tell you how serious things are. That’s where an echocardiogram comes in.
An echocardiogram lets a veterinary cardiologist see the pulmonic valve directly, measure blood flow speed, and calculate how hard the right ventricle is working to push blood through the narrowing. That number determines the severity grade:
| Grade | Pressure gradient | What it means |
|---|---|---|
| Mild | Below 50 mmHg | Usually no treatment needed, just monitoring |
| Moderate | 50 to 80 mmHg | May or may not require intervention depending on symptoms |
| Severe | Above 80 mmHg | Treatment is generally recommended |
Your vet may also recommend chest X-rays to check heart size and look for fluid, and an ECG if there are concerns about abnormal heart rhythms.
What are the treatment options for pulmonic stenosis?
Treatment depends entirely on the severity grade assigned after the echocardiogram.
Mild cases
Dogs with mild pulmonic stenosis typically don’t need medication or surgery. Your vet will likely recommend a recheck echocardiogram every year or two to make sure the pressure gradient isn’t changing. Many of these dogs have a normal life expectancy.
Severe cases: balloon valvuloplasty
For dogs with severe pulmonic stenosis, the most commonly recommended treatment is balloon valvuloplasty. A cardiologist threads a thin catheter through a blood vessel to the heart, then inflates a small balloon at the narrowed valve to widen it. It’s not open-heart surgery, but it does require general anesthesia and a specialist facility.
Balloon valvuloplasty doesn’t fix the valve completely, but it significantly reduces the pressure on the right ventricle in most dogs. Many dogs show clear improvement in energy and quality of life afterward. Some dogs may also be prescribed medication to support heart function or manage fluid buildup alongside or instead of surgery.
Does pet insurance cover pulmonic stenosis in dogs?
Yes, pulmonic stenosis is eligible for coverage under a Lemonade Pet accident and illness policy, when the condition isn’t pre-existing. That means your puppy shouldn’t have a documented murmur or any related symptoms before your policy starts or during your waiting period.
An echocardiogram from a veterinary cardiologist can run several hundred dollars, and balloon valvuloplasty typically costs $3,000 to $6,000 or more depending on your location and facility. Enrolling your puppy before any murmur is flagged is what keeps those costs eligible for coverage.
Before we go
A pulmonic stenosis diagnosis is a lot to absorb, but knowing your dog’s severity grade, what to watch for at home, and what treatment looks like puts you in a much better position. Keep up with the recheck echocardiograms, track that resting respiratory rate, and don’t hesitate to call your vet if something seems off. Many dogs with pulmonic stenosis live full, comfortable lives, especially when it’s caught early and managed well.
Frequently Asked Questions
What is the life expectancy of a dog with pulmonic stenosis?
Dogs with mild pulmonic stenosis often have a normal life expectancy with routine monitoring. Dogs with severe cases that go untreated face a higher risk of early heart failure, but those who respond well to balloon valvuloplasty can also live full lives. Your cardiologist is the best source for a realistic picture based on your dog’s specific pressure gradient and overall health.
Is balloon valvuloplasty a cure for pulmonic stenosis in dogs?
It’s not a cure, but it’s the most effective treatment available for severe cases. The procedure widens the narrowed valve opening, which significantly reduces the workload on the right ventricle. Most dogs improve meaningfully after the procedure, though some degree of narrowing typically remains.
Which dog breeds are most at risk for pulmonic stenosis?
Bulldogs, Boxers, and Beagles are among the most commonly affected breeds, along with West Highland White Terriers, Mastiffs, Samoyeds, and Miniature Schnauzers. Because the condition is hereditary, dogs diagnosed with it should not be bred.
Can a dog with pulmonic stenosis exercise normally?
It depends on the severity grade. Dogs with mild pulmonic stenosis can usually exercise normally, while those with severe cases should be kept to gentle, low-key activity until they’ve been evaluated and treated. Always check with your veterinary cardiologist before setting exercise limits.
How do I monitor my dog with pulmonic stenosis at home?
Track your dog’s resting respiratory rate (normal is 15–30 breaths per minute while asleep or fully relaxed), log any fainting episodes with details about what happened before and after, and watch for changes in energy level or belly size. Report anything unusual to your vet promptly.
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