Pimobendan for Dogs: A Medicine to Manage Heart Failure

Heart failure is a disease commonly diagnosed in older, smaller-breed dogs. It causes symptoms such as coughing and the inability to exercise. And it negatively impacts the quality of life and lifespan for dogs diagnosed with the condition. 

The good news is that now there are safe, effective medications including pimobendan (Vetmedin) for dogs. Pimobendan can minimize symptoms and slow the progression of congestive heart failure. 

In this article, you will learn what pimobendan is, how it works, its potential side effects, and what to do if you miss giving your dog a dose. 

Pimobendan for dogs at a glance

What is pimobendan for dogs, and how does it work?

Pimobendan is a benzimidazole-pyridazinone derivative medication. It improves how well the heart muscles contract and lowers blood pressure by dilating peripheral blood vessels.

What is pimobendan used for in dogs?

Pimobendan is FDA-approved for dogs with congestive heart failure due to myxomatous mitral valve disease or dilated cardiomyopathy. 

Myxomatous mitral valve disease (MMVD) causes the mitral valve in the heart’s left ventricle to decline. This causes blood to leak backward when the heart muscles squeeze. MMVD accounts for about 75% of all heart disease in dogs. Small- and medium-sized dog breeds are at highest risk for MMVD.

Dilated cardiomyopathy (DCM) is a disease of the heart muscles themselves. It causes a weakened heart that cannot effectively pump blood. 

Both MMVD and DCM eventually lead to congestive heart failure, which causes: 

• Enlarged heart

• Difficulty breathing

• Panting

• Coughing

• Difficulty exercising

• Weakness

• Collapse

• Pale gums 

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Neither of these heart diseases are curable. But pimobendan is a medication that can help manage the symptoms of heart failure in dogs. As a result, your pup will have fewer heart-related symptoms, and their lifespan may be increased.

Pimobendan is also available in a new formulation that is conditionally FDA-approved called Vetmedin-CA1. It’s designed to slow the progression of mitral valve disease and delay the onset of heart failure in dogs. 

What is the dosage of pimobendan for dogs, and how is it given?

Pimobendan is available for dogs by prescription from a veterinarian. It comes in the following forms:

• Chewable flavored tablet

• Tablet

• Capsule

• Flavored oral liquid 

The typical dosage of pimobendan for dogs is 0.25 mg to 0.3 mg per kilogram of body weight. Your veterinarian will determine the correct dosage for your dog. The medication is given in two doses 12 hours apart. 

The medication can be crushed to make it easier to give to your dog. It can be given with or without food. 

What should you do if your dog misses a dose of pimobendan?

If you miss giving your dog a dose of pimobendan, give them the next dose as soon as you remember. Then resume their regular dosing schedule. 

If it is close to the time of your dog’s next dose, skip the missed dose. Then give the next dose at the regular time. 

Never give two doses at the same time to make up for a missed dose. If you have any questions or feel concerned, contact your veterinarian for advice.

What are the common side effects of pimobendan in dogs?

Dogs taking pimobendan may experience the following side effects:

• Loss of appetite

• Lack of energy

• Diarrhea

• Vomiting

In general, pimobendan appears to be safe and well tolerated by most dogs. Adverse effects are relatively rare and are mostly related to gastrointestinal upset.

What are the most serious risks of pimobendan for dogs?

Some serious risks have been reported in dogs taking pimobendan. These risks include:

• Shortness of breath

• Weakness

• Wobbly gait

• Too much waste circulating in the blood

• Fluid in the lungs or abdomen

• Fainting

• Cough

• Heart murmur

• Sudden death

Some of these reported risks are also symptoms of heart failure. So some of these serious symptoms may be related to the progression of a dog’s heart disease rather than the medication itself.

Pimobendan should not be used, or should be used with extreme caution, in dogs with congestive heart failure due to an outflow obstruction. This includes dogs diagnosed with:

• Subaortic stenosis

• Pulmonic stenosis

• Systolic anterior motion of the mitral valve

• Asymmetric septal hypertrophy

• Pericardial effusion

The safety of pimobendan has not been tested in dogs younger than 6 months old.

Does pimobendan interact with any other dog medications?

Pimobendan generally does not interact with other dog medications. It can be safely given with other heart medications, including diuretics, ace inhibitors, and digoxin. 

Using pimobendan at the same time as a beta blocker or calcium channel blocker may prevent pimobendan from working as well as it should. It’s usually not recommended for dogs taking these medications. Examples of beta and calcium channel blockers include:

• Propranolol 

• Atenolol

• Verapamil

• Diltiazem 

Before your dog is prescribed pimobendan, make sure your veterinarian is aware of any other medications and supplements your dog takes.

Why trust our experts?

Written by:

Sarah J. Wooten, DVM, CVJ

Dr. Sarah Wooten, DVM, CVJ, is a well-known international influencer in the veterinary and animal healthcare spaces. She has 16 years of experience in private practice and more than 15 years experience in veterinary media work.

Edited by:

Renée Fabian, MA

Renée Fabian is the senior pet health editor at GoodRx. She’s worked for nearly 10 years as a journalist and editor across a wide range of health and well-being topics.

Reviewed by:

Ghanasyam Bey, DVM

Ghanasyam Bey, DVM, is from Cleveland, Ohio, and attended Princeton University for undergraduate studies. After a year of biology research at Duke University, he attended Ohio State College of Veterinary Medicine.

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