Heart disease (mitral valve disease) in dogs
The most common heart disease in dogs is degeneration of the mitral valve, which lets blood leak backward. It's especially common in small breeds like Cavalier King Charles Spaniels.
Last updated: October 2026 · 3 sources · see sources
Signs to watch for
- A heart murmur found at a checkup
- Coughing
- Faster breathing at rest or asleep
- Tiring easily
- Fainting
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
Your vet listens for a murmur and may recommend chest X-rays, blood pressure, an NT-proBNP blood test and an echocardiogram. [2][3]
How it's treated
Some dogs benefit from starting pimobendan before signs appear. Dogs in heart failure also get diuretics like furosemide and other heart medicines. [2][3]
Medicines your vet may mention: Vetmedin (Pimobendan), Furosemide (Lasix), Enalapril, Spironolactone. 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) | $500–$1,200 | [1] |
| Ongoing treatment, per month | $50–$300 | [1] |
| Ongoing treatment over a year (monthly range × 12) | $600–$3,600 | [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
Many dogs live a long time with a murmur. Counting resting breaths at home helps catch heart failure early. [2][3]
Common questions
What is heart disease (mitral valve disease) in dogs?
The most common heart disease in dogs is degeneration of the mitral valve, which lets blood leak backward. It's especially common in small breeds like Cavalier King Charles Spaniels.
What are the signs of heart disease (mitral valve disease)?
Common signs include: a heart murmur found at a checkup, coughing, faster breathing at rest or asleep, tiring easily, fainting.
How do vets diagnose heart disease (mitral valve disease)?
Your vet listens for a murmur and may recommend chest X-rays, blood pressure, an NT-proBNP blood test and an echocardiogram.
How is heart disease (mitral valve disease) treated?
Some dogs benefit from starting pimobendan before signs appear. Dogs in heart failure also get diuretics like furosemide and other heart medicines.
How much does heart disease (mitral valve disease) cost to treat?
Diagnosis (exam and tests): $500–$1,200; Ongoing treatment, per month: $50–$300; Ongoing treatment over a year (monthly range × 12): $600–$3,600. 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.