My Dog Has A Heart Murmur, Now What?

Posted 03.23.17 by Katie Willis

Don’t panic! Heart murmurs are quite common in dogs, and many live a normal life span. Murmurs are diagnosed when your veterinarian listens to the heart during the physical exam. Breeds that are more likely to develop a murmur include Cavalier King Charles Spaniels, German Shepherds, Doberman Pinschers, Poodles, Cocker Spaniels, and Yorkshire Terriers. A murmur can be caused by a structural abnormality of the heart, or it can be “innocent” or “physiologic”, meaning there is no structural change to the heart. “Innocent” murmurs can be caused by other systemic issues, such as anemia, that when corrected, the murmur disappears. Puppies also can be born with a murmur that may go away as they mature. Most often in dogs, however, the cause is from degeneration of the heart valves and vessels. These changes can be present from birth, or can be acquired with age. Middle aged to older small and toy breed dogs are most likely to develop valvular degeneration, typically of the mitral valve.

Murmurs are graded on a scale from 1-6, with 1 being very quiet, and 6 being so loud that you can feel it through the chest. Unfortunately, we cannot tell severity of disease based on the grade of murmur. If your veterinarian hears a murmur, they may start by recommending x-rays to look for any signs of heart enlargement, and to evaluate the lungs and vessels in the chest. While x-rays are helpful for evaluating a murmur, the best test to determine cause of a murmur is called an echocardiogram, which is an ultrasound of the heart and its vessels. This allows the veterinarian to identify which valve is leaking, how severe the change is, and how well the heart is coping with the change.

If your dog has been diagnosed with a heart murmur, or any other heart condition, there will be things for you to monitor at home. Coughing, tiring more easily after exercise, increased respiratory rate, and increased effort to breathe are signs that heart disease may be progressing. Depending on clinical signs and diagnostic findings, your veterinarian will work with you to come up with the best treatment plan and follow up schedule for your dog.

Just because your dog has been diagnosed with a heart murmur, heart disease, or any other heart problem does not mean your dog is in heart failure. Heart failure is when fluid accumulates within either the chest or the abdomen, and this occurs with advanced heart disease. Heart failure and heart disease can also be caused by heartworm disease, so making sure your dog is on a good heartworm prevention is crucial.

Many dogs live a long time after being diagnosed with a heart murmur, and some can even live years after being diagnosed with heart failure. If you have any questions or concerns about murmurs, please contact your veterinarian.

Dr. Apryl Barton

The Pet Hospitals- Poplar @ Massey