Heart Murmurs in Dogs: Canine Cardiac Murmurs

By Jennifer Gauntt Texas A&M University, September 2021
heart murmur in dogs

Dog owners do not need to be veterinarians to know that a healthy heart is as important for our furry friends as it is for humans. Yet there can be a lot of confusion surrounding cardiac issues in animals, especially when it comes to heart murmurs. 

Dr. Sonya Wesselowski, an assistant professor of cardiology at the Texas A&M College of Veterinary Medicine & Biomedical Sciences, offers insight on murmurs, given her expertise in the diagnosis and treatment of cardiovascular disease in animals. 

Wesselowski describes a heart murmur as “an extra whooshing sound” heard during a heartbeat that is typically caused by turbulent or rapid blood flow inside the heart. Some murmurs are considered to be harmless, or “physiologic,” while other murmurs are considered “pathologic,” or disease-related. In dogs, common reasons for a disease-related heart murmur include leaky or narrowed heart valves.  

Not all heart murmurs are dangerous, though. 

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“Some soft heart murmurs can be normal in young puppies under 4-6 months of age,” Wesselowski said. “The majority of heart murmurs, however, do indicate that some sort of heart abnormality is present.

“This might be a congenital abnormality that a dog was born with or an ‘acquired’ heart disease that developed later in life, with these diseases ranging from mild to severe,” she said.  

Luckily, if your pup is found to have a heart murmur, there are likely some good treatment options to keep their heart healthy and pumping for as long as possible.  

Step one, however, is confirming a diagnosis. 

“If your veterinarian identifies a heart murmur in your dog, additional testing should be pursued to determine the type and severity of any underlying heart problems,” Wesselowski said. “The heart murmur itself should be thought of as a red flag that possible heart disease is present, but it can’t speak to the severity of any underlying heart problems, so additional testing is needed to sort out the next best steps.

“Some types of heart disease can remain mild for the life of a pet without ever requiring treatment, while others may result in symptoms of heart disease that require cardiac medications, lifestyle changes, and/or diet modifications to combat,” she said. “Additional testing can help sort out which of these scenarios may be the case for your dog.”

The heart is one of the hardest-working organs in the body. Depending on the results of diagnostic tests, your veterinarian will discuss the prognosis and treatment options available for your dog. 

In all cases in which heart disease is identified, it will also be necessary to monitor the condition on a regular basis and to perform periodic diagnostic testing to guide future care. 

It is important for owners to not lose heart when it comes to cardiac disease in dogs. With the right treatments, monitoring, and veterinary team working together, owners can keep their beloved dogs active and happy, even in the face of heart disease.

Photo: Josh Sorenson / Unsplash

This story was originally published by, Pet Talk, a service of the College of Veterinary Medicine & Biomedical Sciences, Texas A&M University. Original stories can be viewed on the web at vetmed.tamu.edu/news/pet-talk. Reprinted with permission. May be edited for style and length.