Subaortic stenosis in dogs
Subaortic stenosis is a narrowing below the aortic valve that makes the heart work harder. It's an inherited condition seen in breeds like Newfoundlands, Golden Retrievers and Boxers.
Last updated: October 2026 · 2 sources · see sources
Signs to watch for
- A murmur in a young dog
- Tiring with exercise
- Fainting
- Sometimes no signs
Trouble breathing, collapse, repeated vomiting, not peeing, or a seizure that lasts more than a few minutes needs a vet right away. See when to see a vet.
How vets diagnose it
An echocardiogram confirms the narrowing and measures how severe it is. [2]
How it's treated
Mild cases may need only monitoring. Some dogs get beta-blockers like atenolol, and exercise may be limited in severe cases. [2]
Medicines your vet may mention: Atenolol. We don't list doses; your vet will decide what fits your pet.
What it costs to diagnose and manage
| Item | Typical US price | Src |
|---|---|---|
| Diagnosis (exam and tests) | $300–$600 | [1] |
| Ongoing treatment, per month | $50–$200 | [1] |
| Ongoing treatment over a year (monthly range × 12) | $600–$2,400 | [1] |
These are typical US ranges from the sources listed. Your pet's costs depend on how severe things are, the tests your vet recommends, your pet's size and where you live. Ask your vet for a written estimate.
Outlook
Mild cases often live normally. Severe cases carry more risk, so ask your cardiologist about activity limits. [2]
Common questions
What is subaortic stenosis in dogs?
Subaortic stenosis is a narrowing below the aortic valve that makes the heart work harder. It's an inherited condition seen in breeds like Newfoundlands, Golden Retrievers and Boxers.
What are the signs of subaortic stenosis?
Common signs include: a murmur in a young dog, tiring with exercise, fainting, sometimes no signs.
How do vets diagnose subaortic stenosis?
An echocardiogram confirms the narrowing and measures how severe it is.
How is subaortic stenosis treated?
Mild cases may need only monitoring. Some dogs get beta-blockers like atenolol, and exercise may be limited in severe cases.
How much does subaortic stenosis cost to treat?
Diagnosis (exam and tests): $300–$600; Ongoing treatment, per month: $50–$200; Ongoing treatment over a year (monthly range × 12): $600–$2,400. Costs vary with severity, tests, your pet's size and where you live.
Related
This page is general information for pet owners, not veterinary advice. Talk to your vet about your own pet.