Help! My Puppy Has a Heart Murmur! (Vet Answered)
This question has been answered by a vet
Veterinarian & Animal Behaviorist
With nearly two decades in veterinary medicine, Dr. Paola brings hands-on experience across multiple species. A graduate of the University of Guadalajara, she specializes in preventive care, animal welfare, and positive reinforcement training.
The Question
“Hi Dr. Paola,
My new 9-week-old Sheltie puppy was just diagnosed with a heart murmur with a grade of 5/6. On our vet’s recommendation, we are trying to get an appointment with a cardiologist at Auburn University, whom she knows. In the meantime, how can we help Blondie to be her best? She loves rough house playing with our other two sheltie puppies. She’s a tough little cookie and usually starts it. Is this dangerous for her with the murmur? Nobody has ever hurt anybody. I watch to make sure she’s not panting or passing out. And she hasn’t. What do I do if she did? I feed them a good dog food, dry, freeze-dried with only good ingredients, including ginger and chicory. Fresh water all day. What else can I do? Do I need to be aware that this condition may be fatal? How
likely? Thank you.” – Becky
Quick Info about Blondie
Dear Becky,
This is understandably frightening news, especially with such a young puppy, and you are doing exactly the right thing by pursuing a cardiology evaluation promptly. A grade 5 out of 6 heart murmur in a 9-week-old puppy is considered loud and clinically significant, which means it is very likely associated with an underlying structural heart condition rather than a benign puppy murmur. That does not automatically mean it is fatal, but it does mean Blondie’s heart is working under different rules, much like an engine with a loud knock that needs a specialist to determine whether it is fixable, manageable, or progressive.
Until she is evaluated by a cardiologist, activity should be moderated rather than eliminated. Short, calm play is usually acceptable, but intense roughhousing that leads to sustained excitement, heavy exertion, or prolonged chasing is best limited for now, even if she initiates it. Puppies do not self-regulate well, especially confident ones. Watching for signs like excessive panting at rest, weakness, coughing, pale gums, or sudden collapse is important. If she were to collapse or appear faint, she should be kept calm and cool and seen by a veterinarian or emergency clinic immediately, as those signs suggest her heart may not be keeping up with her body’s demands.
Nutrition and hydration sound appropriate, and at this stage, there is no evidence-based supplement or ingredient that will correct a congenital heart defect, so avoiding unnecessary additions is wise. The most helpful things you can do right now are protecting her from overexertion, minimizing stress, and keeping that cardiology appointment a priority. Once a definitive diagnosis is made, you will have a much clearer picture of prognosis and options, and many dogs with early-detected heart disease can still enjoy a good quality of life with proper management.
Best wishes,