Heart Murmurs in Dogs – Whole Dog Journal

Many dogs with heart murmurs have no symptoms. Most heart murmurs in dogs are picked up by the veterinarian during routine physical exams on apparently healthy, asymptomatic dogs and puppies. Many heart murmurs in dogs will never cause a problem. For those that do, medications can help.

Heart Murmurs in Puppies

Benign or “innocent” murmurs in puppies do not shorten life expectancy. There are, however, some cardiac birth defects in puppies that are bad. These puppies will not thrive, and many will not survive without surgical correction of the defect. Thankfully, these cases are few and far between.

Treatment

Most dogs with heart murmurs can live long and healthy lives, but it depends on how early the murmur is identified and how carefully the dog is monitored.

Monitoring dogs with heart murmurs includes frequent physical examinations and echocardiography at least once a year. The earlier any evidence of heart disease is identified, and treatment initiated, the longer the dog will live, with many surviving five years or more.

From Murmur to Congestive Heart Failure

Congestive heart failure (CHF) is what happens most commonly when a heart murmur in a dog becomes problematic. Watch for these symptoms:

• Cough: Usually a soft, wet-sounding cough from the chest, may be worse after lying down or first thing in the morning
• Difficulty breathing: Heavy breathing, rapid respiratory rate, anxious panting, distressed appearance.
• Exercise intolerance: Doesn’t want to go for walks or quits after a short time; walks take a lot longer than usual as the dog cannot walk as quickly as before.
• Restlessness when laying down: Fluid builds up in the lungs when the dog is inactive so the dog may shift positions frequently to find the position that best helps him breathe.
• Bluish or grayish color to the tongue and gums: Due to the low blood oxygen levels that occur when the heart no longer efficiently pumps blood through the lungs and body.
• Low energy/fatigue
• Fainting/collapse

CHF Treatment

Treatment for CHF in dogs typically include varying combinations of medications to move fluid out of the lungs (diuretics); medications that make it easier for the heart to pump blood through the vessels (blood pressure drugs); and pimobendan, an inodilator that both strengthens the heart muscle and dilates blood vessels, significantly improving overall cardiac function.