A Series About Heart Failure: Vetmedin

Why is Vetmedin used in heart failure?

Heart failure is a very complicated disease in dogs and often requires multiple medications. The medications used in heart failure can be difficult to understand. This article aims to address one of the medications used in congestive heart failure, called Vetmedin. Vetmedin is the brand name product for the drug pimobendan but there is no generic currently available. It is important to thoroughly discuss all aspects of Vetmedin and the other medications used in heart failure, so the series will be broken up by class for each article.

Vetmedin for Congestive Heart Failure in Dogs

Vetmedin belongs to a class of drugs called phosphodiesterase III inhibitors (also known as PDE III inhibitors). Along with the human drug, milronone, it is used in dogs with congestive heart failure. PDE III is an enzyme found in the body that usually degrades cAMP. By inhibiting the breakdown of cAMP, PDE III inhibitors increase the force of contraction the heart has each time it beats, as well as relaxes the blood vessels  it pumps blood to. Vetmedin can also slow down the heart so the ventricles can fill with more blood. Vetmedin can help in two different ways;  helps the heart get more blood out to the rest of the body and decreases the resistance it has to pump against. By doing this, it helps with the symptoms of heart failure in dogs, but it does not cure it. Vetmedin has a benefit of not increasing the calcium levels inside the heart cells, making it safer compared to other drugs like milrinone. This is why Vetmedin is used much more commonly in dogs, and VetRxDirect does not carry milrinone.

What are some important things I should know about Vetmedin?

Since Vetmedin increases the force the heart has, it can also cause the heart to get off rhythm which is also called arrhythmias. Vetmedin also relaxes the arteries which may cause low blood pressure leading to falling or fainting. Less serious side effects of Vetmedin include hyperactivity, drooling, and constipation, rash, and anemia. There are also a few reports of Vetmedin causing diabetes. As with most drugs, but especially drugs for heart failure, it is important to weigh the benefits and risks of taking the medication. If you are concerned about the side effects of Vetmedin, consult your veterinarian to see if they think the side effects are likely to happen.

How should I monitor my dog while they’re on Vetmedin?

While your dog is on Vetmedin you should monitor their general mood. Often times, owners can tell if their pet isn’t feeling well. Since this could indicate worsening heart failure or side effects of Vetmedin, it is important to keep in contact with your veterinarian about their overall mood. Vetmedin has a narrow dosage range and overdosage can occur somewhat easier than other medications. Signs your dog may be overdosed on Vetmedin include vomiting, diarrhea, and loss of appetite. If your dog experiences any of these symptoms you need to call your dog’s veterinarian.

What’s new about Vetmedin?

Vetmedin is now available in more dosages from VetRxDirect to tailor to more dogs and thier needs. Vetmedin now comes in 1.25mg, 2.5mg, 5mg and 10mg doses!

This article only addresses one of the medications your dog might be on for congestive heart failure. Tune in for articles about all of the other medications used to better understand the medications your dog may use.

Is your dog on Vetmedin? How has it helped with his or her congestive heart failure? Please leave any remaining questions you have by leaving a reply below. Thank you.


  • Plumb, D. Pimobendan. Plumb’s Veterinary Drug Handbook 7th ed. Pharma Vet Inc. Stockholm, WI. 2011. Pages 637-638
  • Vetmedin www.Vetmedin.com. Accessed 05/01/2014.