Golden Retriever Heart Problems: SAS, DCM, Murmurs and Signs to Watch

Most golden retrievers have strong, healthy hearts for life. But the breed does have a few heart conditions worth knowing about: one that’s inherited and present from birth, one that’s been linked to diet, and one that usually shows up suddenly in older dogs. Knowing the basics helps you ask the right questions of your breeder and your vet.

General education only. Heart disease can only be diagnosed by a veterinarian. If you notice any of the signs below, call your vet. If your dog collapses or struggles to breathe, go to an emergency vet right away.

The heart conditions goldens are prone to

Condition	What it is	Typical age
Subaortic stenosis (SAS)	An inherited narrowing just below the aortic valve that makes the heart work harder	Present at birth; a murmur is often found in puppyhood
Dilated cardiomyopathy (DCM)	The heart muscle thins and weakens, and the chambers enlarge. In goldens it’s often linked to low taurine	Usually adults
Pericardial effusion	Fluid builds up in the sac around the heart, often from a tumor	Middle-aged and older dogs

Other heart conditions can affect any dog, including goldens. Tufts’ Cummings School of Veterinary Medicine notes that heartworm disease, spread by mosquitoes, is easy to prevent and much harder to treat. Ask your vet about year-round prevention.

Subaortic stenosis (SAS)

SAS is a congenital defect, which means the dog is born with it. A ridge of tissue narrows the outflow path below the aortic valve, so the left side of the heart has to push harder to get blood out to the body. Over time the heart wall thickens.

• Goldens are a predisposed breed. VCA Animal Hospitals lists the golden retriever among the breeds most commonly affected, and Tufts lists goldens among breeds with a known predisposition.
• It isn’t common in the breed, but it can be serious. The Golden Retriever Club of America (GRCA) says a small percentage of goldens are affected.
• Many dogs never show signs. Tufts says most puppies with SAS show no symptoms and are diagnosed only after a vet hears a murmur. VCA notes that in mild cases the murmur may not be heard until 6 to 12 months of age.
• Severity varies a lot. According to Tufts, dogs with mild SAS and no symptoms usually live a normal lifespan without treatment. Severe SAS can cause fainting, heart failure or sudden death.

How it’s diagnosed: an echocardiogram (heart ultrasound), ideally by a veterinary cardiologist, is the best test. It shows the narrowing and measures how much pressure the heart has to generate, which helps your vet judge severity.

How it’s managed: mild cases often need monitoring only. For moderate to severe SAS, cardiologists may prescribe medication such as a beta-blocker, and a few specialty centers offer balloon procedures. VCA advises restricting strenuous exercise in affected dogs, especially those with severe disease. Your vet or cardiologist will tailor the plan to your dog.

Because SAS is inherited, affected dogs should not be bred. That’s why heart screening of the parents matters (more on that below).

Dilated cardiomyopathy (DCM) and taurine

In DCM, the heart muscle becomes thin and weak, the chambers stretch, and the heart can’t pump well. Tufts calls DCM the most common heart disease in large-breed dogs. It can lead to congestive heart failure (fluid in the lungs) and dangerous heart rhythms.

Goldens have a particular story here:

• Low taurine. Tufts notes that goldens may develop DCM partly because of taurine deficiency. Taurine is an amino acid that dogs normally make from other nutrients in their food.
• A link with certain diets. In a 2018 multicenter study published in PLOS ONE, researchers including UC Davis cardiologist Dr. Joshua Stern followed 24 goldens with taurine deficiency and DCM. 23 of the 24 were eating grain-free diets, legume-rich diets or both. The authors concluded the problem is likely multifactorial, with dietary, metabolic and genetic factors all playing a role.
• Often reversible when caught. In that study, 23 of 24 dogs improved significantly on echocardiogram after a diet change plus taurine supplementation. That’s unusual: Tufts says most DCM isn’t reversible, with diet-associated DCM the exception in some cases.
• No proven cause yet. The FDA investigated reports of DCM in dogs eating certain diets, many labeled grain-free and high in peas, lentils or potatoes. It described a complex, possible association rather than a proven cause. The FDA also noted that goldens may be over-represented in reports partly because breed communities raised awareness. In December 2022 it said it doesn’t plan further public updates until there’s meaningful new science.

What this means for you: don’t panic about your dog’s food, and don’t start taurine supplements on your own. Instead, bring your food bag (and a list of treats and chews) to your next vet visit and ask whether the diet is a good choice for a golden. The FDA suggests that owners of goldens who may be affected talk with their vet about checking taurine levels or getting an echocardiogram. For more on choosing a food, see our guide to the best food for golden retrievers.

Fluid around the heart (pericardial effusion)

Tufts lists the golden retriever among the breeds most prone to pericardial effusion, where fluid fills the sac around the heart and stops it from filling properly. A common cause is hemangiosarcoma, a cancer that often grows on the right atrium of the heart and bleeds into that sac. It’s usually found in middle-aged and older dogs, often only once it’s an emergency.

Signs include sudden weakness or collapse, trouble breathing, pale gums and a swollen belly. This is an emergency. Our golden retriever cancer guide explains more about hemangiosarcoma.

What a heart murmur means

A murmur is an abnormal “whooshing” sound your vet hears through the stethoscope, caused by turbulent blood flow. VCA explains that:

• Murmurs are graded from 1 (very soft) to 6 (very loud), but loudness doesn’t always tell you how serious the cause is.
• Many fast-growing large-breed puppies have an innocent murmur. It may appear at 6 to 8 weeks and usually goes away by about 4 to 5 months of age. These are generally quiet (grade 1 to 2) and cause no signs of illness.
• Other murmurs come from structural heart disease, such as SAS, or from problems outside the heart, like anemia or fever.

If your vet hears a murmur in your golden puppy, they may suggest a recheck in a few weeks. If it persists or is loud, ask whether a referral to a veterinary cardiologist for an echocardiogram makes sense.

Warning signs to watch for

Early heart disease often has no signs at all. As it progresses, look for:

• Tiring easily or lagging behind on walks
• Coughing, especially at night or after lying down
• Faster or harder breathing while resting or asleep
• Fainting or collapse
• Poor appetite or weight loss (or slow growth in a puppy)
• Pale or grayish gums
• A swollen belly

Go to an emergency vet right away if your golden collapses, has trouble breathing, has pale gums or suddenly becomes very weak.

Counting your dog’s sleeping breathing rate

If your vet asks you to monitor your dog’s heart at home, a simple tool is the resting or sleeping breathing rate. VCA says a normal rate while resting calmly or asleep is about 15 to 30 breaths per minute. Rates that are consistently above 30 are considered increased. Tufts suggests counting breaths for 30 seconds and doubling the number, and checking only when your dog is calm and not panting. Ask your vet what rate should prompt a call for your dog in particular.

Screening: what to ask a breeder

Since SAS is inherited, responsible breeders screen their dogs’ hearts before breeding:

• GRCA recommends that every prospective breeding golden be examined at 12 months or older by a board-certified veterinary cardiologist. If a murmur is found, further tests may be recommended.
• Normal results should be on public record. GRCA says normal cardiac exams should be certified by the Orthopedic Foundation for Animals (OFA), and you can look up a dog by its registered name or number.
• The OFA’s Advanced Cardiac Database uses exams by veterinary cardiologists and issues a congenital clearance, which is considered permanent, and an adult-onset clearance that’s valid for one year.

Screening lowers the risk but can’t bring it to zero. Our guide to choosing a golden retriever breeder covers all the health clearances to ask for.

Keeping your golden’s heart healthy

• Keep up with regular vet checkups, which include listening to the heart. Ask your vet how often your golden should be seen.
• Give heartworm prevention as your vet recommends.
• Keep your dog lean. Extra weight puts more strain on the body. See our guide to an overweight golden.
• Talk to your vet about diet before choosing a grain-free, boutique or homemade diet.
• Learn your dog’s normal: energy on walks, breathing at rest and gum color, so you notice changes early.

Bringing home a golden puppy? Our free puppy checklist helps you plan vet visits and keep health records from day one, including any murmur your vet notes at puppy checkups.

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