Heart Murmurs

Heart Murmurs

Heart murmurs are a quite common condition in dogs, and occasionally cats. No obvious signs of heart disease may be present and many pets with a heart murmur will continue to lead a normal life for years. At this stage, no treatment is necessary.

In the future, the condition may be progressive and Congestive Heart Failure (CHF) can develop. When this occurs, medication and lifestyle changes will be required to manage the disease.

The good news is that your dog may not show any signs of CHF for many years.

What is a Heart Murmur?

Valves within the heart open to allow blood to the heart chamber , then close forming a seal against back flow of blood as the heart contracts. This ensures that all blood moves forward to supply the body with oxygen and nutrients.

A heart murmur is an indication that these valves, which normally prevent “backflow” of blood, are not closing properly. Blood is then able to leak “backwards” when the heart contracts. This creates the noise we hear as a murmur with our stethoscope. The valve defect is usually due to a slight change in the shape of the valves. The cause of this in most cases is unknown, although there may be a hereditary component.

Eventually, as this “backflow” of blood increases, the heart has to work harder to pump blood. As the disease worsens the heart may not be able to supply enough blood to the body for your pet to maintain a normal active life.

How do I know when it is time to begin treatment?

All cases of heart disease will eventually progress and most will require treatment.

These are the signs to look out for:

Early Signs:

  • Coughing (usually a hacking cough)
  • Shortness of breath
  • Loss of alertness
  • Reduced appetite
  • Weight loss

Advanced Signs:

  • Pale gums
  • Pot belly
  • Severe exercise intolerance
  • Difficulty breathing
  • Fainting

The sooner treatment is started, the more successful it will be, and current heart medications can substantially increase the quality of your pets’ life.