What Are the Side Effects of Vetmedin in Dogs?

By Betty Lewis

If your dog suffers from congestive heart failure, he may benefit from the drug Vetmedin, or its generic counterpart pimobendan. The drug gained favor in Europe for its favorable effects, including quick resolution of symptoms and improved longevity. Though there are potential side effects, generally Vetmedin is safe for dogs and is often part of a lifelong treatment regimen if it improves the quality of life for a dog with heart failure.

Vetmedin for Heart Disease

If your dog has congestive heart failure related to dilated cardiomyopathy or degenerative mitral valve disease, your vet may prescribe pimobendan. Known by the brand name Vetmedin, this heart medication is an inodilator, helping the heart pump efficiently by opening the blood vessels leading to and from the heart. After taking the medication, the dog's heart rate decreases and his heart's contractility -- the ability to contract -- increases. Vetmedin also relieves pressure on the heart.

Vetmedin Side Effects

Vetmedin is available in chewable tablets, in two sizes: 1.25 mg and 5 mg. Typically, the medication is administered every 12 hours, ideally one hour before mealtime. Vomiting is a rare side effect of the drug; diarrhea and loss of appetite may occur. Other potential side effects include loss of coordination, seizures and uneasiness. The heart's ability to contract also may be affected, so the dog taking pimobendan should be monitored for arrhythmia.

Vetmedin Efficacy

It doesn't take long for the drug to make its effectiveness known; VeterinaryPartner.com reports that results have been reported within a week of initiating treatment with pimobendan. If a dog experiences improvement, which usually builds over the course of several weeks, he'll likely take the drug for the rest of his life. VeterinaryPartner.com cited a 2006 study showing the drug's promise: Dogs taking pimobendan gained an extra nine months of life compared to dogs taking other conventional cardiac medication.

Vetmedin Contraindications

Despite the promise of Vetmedin, it's not for every dog. It's not recommended for dogs with aortic stenosis or hypertrophic cardiomyopathy, nor for a dog who had heart disease prior to the onset of congestive heart failure. A dog taking a phosphodiesterase inhibitor should not take pimobendan, though there are no known drug interactions with it. If your dog experiences side effects, or shows signs of allergic reaction, such as hives, facial swelling or difficulty breathing, contact your veterinarian immediately.