Pimobendan: Good for your dog!

By Kevin Pang

Pimobendan introduction

Pimobendan is a veterinary drug for dogs that have mild, moderate, or severe congestive heart failure. It is a prescription drug that can only be obtained through a prescription order from a veterinarian. Pimobendan has proven clinical benefit in preventing arrhythmias, or abnormal heart beats that can lead to sudden cardiac death, in a 56-day field study.

What does congestive heart failure do to my dog?

Congestive heart failure is the heart’s inability to adequately pump blood to other parts of the body. Congestive heart failure for dogs may occur most commonly as a result of weakened heart muscles or a leaky heart valve. Your dog’s age and exercise tolerance are the most important risk factors for developing congestive heart failure. A dog with congestive heart failure most commonly presents with persistent coughing and difficulty breathing. Many dogs with CHF will tire out more easily, have reduced stamina, and do not engage in playing or walking as they once did. Coughing when at rest or sleeping, excessive panting, persistent loss of appetite, a swollen belly, and pale or bluish gums are also signs associated with heart failure.

How does pimobendan work?

Pimobendan increases the sensitivity of heart cells in your dog to pump more strongly without increasing the oxygen demand in the heart. By doing so, the heart is able to compensate for the congestive heart failure symptoms your dog might be experiencing. Pimobendan also causes blood vessels around the body to relax and dilate, increasing blood flow to the tissue and decreasing pressure on the lungs.

Chemical Structure of Pimobendan

What side effects should I know?

While taking pimobendan, your dog may experience side effects. The most common side effects identified in the 56-day field study were poor appetite (38%), lethargy (33%), diarrhea (30%), and difficulty breathing (29%). While the side effects may be troubling, it is important to try to get your dog to continue taking medication to prevent exacerbations of the congestive heart failure. You may want to reach out to your veterinarian for strategies for reducing side effects.

Why might one use compounding for pimobendan?

Compounding is a methodology for creating a new dosage form (such as an oral liquid, topical ointment, or a capsule without specific dyes or preservatives) that is used for medications that are not typically available commercially. Your veterinarian may prescribe doses based on your dog’s health or weight and those doses may not be commercially available. Compounding allows for highly customizable doses. Pimobendan does not come in a scored or easily divisible tablet as well. By compounding this medication, it makes it easier to divide up pills to give to your dog.

References:

1. Pimobendan and Heart Disease | Today. https://todaysveterinarypractice.com/pimobendan-and-heart-disease/.
2. Vetmedin® Package Insert. https://www.bi-vetmedica.com/sites/default/files/dam/internet/ah/vetmedica/com_EN/product_files/vetmedin/vetmedin_label.pdf.
3. Congestive Heart Failure in Dogs | VCA Animal Hospital. https://vcahospitals.com/know-your-pet/congestive-heart-failure-in-dogs.