Vetmedin(®) (pimobendan) is a medicine used for treating dogs with congestive heart failure (CHF). It has two important functions, firstly it opens up the blood vessels which carry blood away from and back to the heart, and secondly it strengthens the beating of the heart. This action is known as “inodilation” and helps to not only reduce the amount of work the heart has to do to pump blood around the body but also allows it to work harder. There are several inodilator medicines but Vetmedin is the first drug approved by the FDA for use in dogs.

How much longer will it help my dog live?

It’s impossible to give exact figures as CHF progresses differently in each dog. However, it should give your dog many more happy days of life than they would have had without the medicine. According to the results of recent trials the drug may also help to prolong the life of dogs who have heart failure due to mitral valve disease.
 

Recommended Dosage

 
Note: This medicine has powerful effects and could be dangerous if given to an unsuitable dog. It should never be used without speaking to your vet first.

The dosage of Vetmedin most often used to treat CHF in dogs is 0.23 mg/lb as a total daily dose. You should split the dosage in half and give twice daily, so if 10 mg of medicine per day is required you would give 5 mg in the morning and 5 mg at night preferably 12 hours apart and about one hour before food. The chart and calculator below should help you.
 

Pimobendan dogs dose chart

Dog’s Weight In Pounds: Dosage In Mg:

 
The actual dosage recommended by your vet may be different, but will usually be between 0.1 – 0.27 mg/lb. Please follow the recommendations of your vet.
 

Example: A 22 lb dog might be given 2.5 mg of medicine twice daily for a total of 5 mg daily.

How Safe Is It?

 
Because the drug is still relatively new there is not much information about the possible risks and complications, though in very rare cases sudden death has been reported. It’s important to avoid giving it to those who will be negatively affected by an increase in cardiac output. Do not give this medicine to dogs with the following conditions:
 

  • Aortic stenosis
  • Hypertrophic cardiomyopathy

 
It may also be unsafe for those with asymptomatic cardiac disease, uncontrolled cardiac arrhythmias, diabetes mellitus or congenital heart defects and for puppies under 6 months of age.

Pregnancy: Pimobendan may be unsuitable for pregnant animals especially when high doses are used, please speak to your vet if your dog is pregnant.
 

Safety Guidelines

 
We recommend following these guidelines for safe treatment with pimobendan:
 

  • Always speak to a vet before beginning treatment
  • Make sure your dog is suitable for Vetmedin (be sure they don’t have aortic stenosis etc.)
  • Make sure your pet’s cardiac function is monitored regularly

 
Cardiac function can be monitored accurately with ECGs, blood pressure tests and echo studies.
 

What Is It Used For?

 
Vetmedin may be useful in prolonging the life of dogs with:
 

  • Congestive heart failure (CHF)
  • Heart failure due to mitral valve disease

 
It should only be considered a treatment, it does not cure these conditions.
 

Side Effects

 
Not much is known about the adverse effects of this drug but the following have been reported:
 
Most Common
 

  • Vomiting
  • Diarrhea
  • Loss of appetite
  • Labored breathing
  • Loss of coordination
  • Weakness
  • Azotemia

 
Other
 

  • Excess fluid around the lungs
  • Loss of consciousness due to low blood pressure
  • Abdominal swelling
  • Heart murmur
  • Coughing
  • Death

 
The effects of an overdose have not been determined.

Sources

Dr. S. Minors
Vetmedin website
Plumb’s Veterinary Drug Handbook (sixth edition)