Vetmedin (pimobendan) is a prescription cardiac medication manufactured by Boehringer Ingelheim that has become the gold standard for managing heart disease in dogs. As an inodilator, Vetmedin has a dual mechanism of action: it strengthens the heart’s contractions (positive inotropy) and dilates blood vessels (vasodilation), improving the heart’s ability to pump blood while reducing its workload. Vetmedin is FDA-approved for the management of congestive heart failure (CHF) in dogs caused by dilated cardiomyopathy (DCM) or myxomatous mitral valve disease (MMVD), and in December 2025, its label was expanded to include a new indication for delaying the onset of CHF in dogs with preclinical Stage B2 MMVD.
What Is Vetmedin Used For?
Vetmedin is prescribed for dogs with specific types of heart disease:
- Congestive heart failure (CHF) caused by dilated cardiomyopathy (DCM) or myxomatous mitral valve disease (MMVD/degenerative mitral valve disease) — this is the original FDA-approved indication
- Preclinical Stage B2 MMVD — as of the December 2025 label expansion, Vetmedin is now approved to delay the onset of clinical signs of heart failure in dogs with advanced preclinical MMVD (echocardiographic evidence of cardiac enlargement but no symptoms yet)
Stage B2 MMVD refers to dogs that have a heart murmur and evidence of heart enlargement on imaging (echocardiogram and/or X-rays) but are not yet showing clinical signs of heart failure such as coughing, difficulty breathing, or exercise intolerance. The EPIC trial (Evaluation of Pimobendan In dogs with Cardiomegaly) demonstrated that pimobendan extended the time to onset of CHF by approximately 15 months in dogs with Stage B2 MMVD.
Vetmedin is not a cure for heart disease. It manages the condition to improve quality of life, extend survival time, and (in the case of Stage B2 MMVD) delay disease progression. Heart disease management in dogs typically involves multiple medications and regular veterinary monitoring.
How Does Vetmedin Work?
Vetmedin works through two complementary mechanisms:
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Positive inotropy (calcium sensitization): Pimobendan increases the sensitivity of cardiac muscle to calcium, which strengthens the heart’s contractions without significantly increasing oxygen demand. This helps the weakened heart pump blood more effectively.
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Vasodilation (phosphodiesterase III inhibition): Pimobendan inhibits the enzyme phosphodiesterase III in heart muscle and blood vessel walls, causing blood vessels to relax and widen. This reduces the resistance the heart has to pump against (afterload) and reduces fluid backing up into the lungs (preload).
This dual action is why pimobendan is called an “inodilator” — it combines inotropic (heart-strengthening) and vasodilatory (vessel-relaxing) effects. The result is improved cardiac output with less strain on the heart.
Dosage
Vetmedin is dosed based on your dog’s body weight. Your veterinarian will determine the exact dose. The FDA-approved dose is 0.23 mg/lb (0.5 mg/kg) total daily dose, divided into two doses given 12 hours apart.
| Dog’s Weight | Total Daily Dose | Per-Dose Amount | Tablet Strength |
|---|---|---|---|
| 5.5 - 11 lbs (2.5 - 5 kg) | 1.25-2.5 mg/day | 0.625-1.25 mg twice daily | 1.25 mg |
| 11 - 22 lbs (5 - 10 kg) | 2.5-5 mg/day | 1.25-2.5 mg twice daily | 1.25 mg or 2.5 mg |
| 22 - 44 lbs (10 - 20 kg) | 5-10 mg/day | 2.5-5 mg twice daily | 2.5 mg or 5 mg |
| 44 - 88 lbs (20 - 40 kg) | 10-20 mg/day | 5-10 mg twice daily | 5 mg or 10 mg |
| Over 88 lbs (40+ kg) | 20+ mg/day | 10+ mg twice daily | 10 mg |
Available strengths: 1.25 mg, 2.5 mg, 5 mg, 10 mg chewable tablets.
How to Give Vetmedin to Your Dog
- Give on an empty stomach — ideally 1 hour before feeding. Food can reduce absorption of pimobendan.
- Give twice daily, approximately 12 hours apart. Consistent timing is important.
- Vetmedin chewable tablets can be given directly or offered as a treat, but should not be mixed with food.
- If you miss a dose, give it as soon as you remember. If it is close to the next scheduled dose, skip the missed dose and resume the regular schedule. Do not double up.
- Never stop Vetmedin suddenly without veterinary guidance, as this could worsen your dog’s heart condition.
- Keep all scheduled follow-up appointments for cardiac monitoring.
Side Effects
Most dogs tolerate Vetmedin well. However, as with all cardiac medications, monitoring is essential.
| Common Side Effects | Serious Side Effects (Contact Your Vet) |
|---|---|
| Decreased appetite | Increased coughing or difficulty breathing (may indicate worsening CHF) |
| Diarrhea | Fainting or collapse |
| Lethargy | Rapid or irregular heartbeat |
| Sudden weakness | |
| Swollen abdomen (fluid accumulation) | |
| Severe vomiting |
Dogs on Vetmedin for heart failure are usually also on other medications (furosemide, ACE inhibitors), so side effects may be related to the combination rather than any single drug. Your veterinarian will determine the cause of any new symptoms.
Drug Interactions
Vetmedin is commonly used alongside other cardiac medications as part of a multi-drug heart failure protocol. Common combinations include:
- Furosemide (Lasix): Loop diuretic to manage fluid accumulation. Standard companion drug.
- Enalapril or benazepril: ACE inhibitors to reduce cardiac workload. Often used with Vetmedin.
- Spironolactone: Potassium-sparing diuretic, sometimes added for additional diuresis.
- Digoxin: May be used for rate control in atrial fibrillation. Use with caution alongside pimobendan and monitor closely.
Inform your veterinarian about all medications and supplements your dog receives, including joint supplements, fish oil, and any other treatments.
Contraindications
Vetmedin should not be used in dogs with:
- Hypertrophic cardiomyopathy (HCM) — pimobendan can worsen outflow obstruction
- Clinical conditions where cardiac output augmentation is inappropriate (such as aortic stenosis), unless directed by a veterinary cardiologist
- Known hypersensitivity to pimobendan
Vetmedin has not been evaluated in dogs used for breeding, or in pregnant or lactating dogs. Your veterinarian or a veterinary cardiologist will confirm that Vetmedin is appropriate for your dog’s specific type of heart disease.
Storage
- Store at controlled room temperature, 68-77 degrees F (20-25 degrees C).
- Keep in the original packaging, protected from moisture.
- Keep out of reach of children and other pets.
Cost & Availability
Vetmedin is a prescription-only medication.
- Approximate monthly cost: $30-$60 per month depending on dog size and dose
- Cost per tablet: Approximately $1 per tablet across most strengths
- Available strengths: 1.25 mg, 2.5 mg, 5 mg, 10 mg
Regarding generics: The first generic pimobendan product received FDA approval in April 2024. Generic pimobendan is becoming available in the US market, which may reduce costs for pet owners. Generic availability can vary by region and pharmacy. Ask your veterinarian or pharmacist about generic options.
Vetmedin and generic pimobendan are available through veterinary clinics and licensed pet pharmacies.
The EPIC Trial and Stage B2 Indication
The landmark EPIC trial (Evaluation of Pimobendan In Cardiomegaly) was a large, multicenter, randomized, placebo-controlled study that evaluated pimobendan in dogs with preclinical MMVD (Stage B2). Key findings:
- Dogs treated with pimobendan reached the primary endpoint (onset of CHF, cardiac death, or euthanasia for cardiac reasons) significantly later than those receiving placebo.
- Median time to onset of CHF was prolonged by approximately 15 months in the pimobendan group.
- The study supported the December 2025 FDA label expansion allowing Vetmedin to be used to delay onset of CHF in Stage B2 dogs.
This means your veterinarian may now recommend starting Vetmedin before your dog shows any signs of heart failure, if imaging shows the heart is already enlarged. Early intervention in Stage B2 MMVD is now part of evidence-based veterinary cardiology guidelines.
Frequently Asked Questions
How long can a dog live on Vetmedin? Survival time varies widely depending on the type and severity of heart disease, the dog’s overall health, and response to treatment. Many dogs with CHF treated with pimobendan alongside other medications live months to years longer than they would without treatment. Dogs started on Vetmedin at Stage B2 (before symptoms) may significantly delay the onset of heart failure. Your veterinarian can provide a more individualized prognosis.
Why does Vetmedin need to be given on an empty stomach? Food can reduce the absorption of pimobendan, making it less effective. Giving it 1 hour before a meal ensures optimal blood levels of the medication.
Is there a generic version of Vetmedin now? Yes. The first generic pimobendan product received FDA approval in April 2024. Availability is increasing, and your veterinarian or pharmacist can advise on whether a generic option is available in your area. Generic pimobendan contains the same active ingredient and is FDA-approved to the same standards.
What is Stage B2 heart disease? Stage B2 is a classification from the ACVIM (American College of Veterinary Internal Medicine) staging system for heart disease. It means your dog has a heart murmur with echocardiographic or radiographic evidence of heart enlargement, but no clinical symptoms yet. It comes after Stage B1 (murmur, no enlargement) and before Stage C (heart failure with symptoms).
Can Vetmedin be used in cats? Pimobendan is sometimes used off-label in cats with certain types of heart disease, but this is not an FDA-approved use and must be done under close veterinary supervision. Cats with hypertrophic cardiomyopathy (the most common feline heart disease) generally should not receive pimobendan.
Sources & References
- FDA FOI Summary - Vetmedin (NADA 141-273)
- ACVIM Consensus Statement - Myxomatous Mitral Valve Disease in Dogs
- Boswood et al. - EPIC Trial Results (J Vet Intern Med, 2016)
- Merck Veterinary Manual - Heart Failure in Dogs
- VCA Hospitals - Pimobendan (Vetmedin)
- Boehringer Ingelheim - Vetmedin Product Information
This content is for informational purposes only and is not a substitute for professional veterinary advice. Always consult your veterinarian before starting, changing, or stopping any medication for your dog.