If you've just been told your dog or cat has a heart murmur, your head is probably spinning. Take a breath — a murmur is a starting point, not a diagnosis, and for many pets here on the Northern Beaches, it's something we can monitor or manage well for years.
First, don't panic. A murmur is a finding, not a diagnosis. It's an invitation to look closer, not an immediate crisis.
A murmur simply means we can hear an extra "whooshing" sound when we listen to your pet's heart, caused by turbulent blood flow rather than the usual quiet, smooth flow. Think of a garden hose: smooth flow is silent, but a kink or a partially-closed nozzle creates a hiss. The heart works the same way.
What causes that turbulence could be something significant, something minor, or sometimes nothing that ever causes a problem. The only way to know is to take a closer look.
In older dogs: The most common cause is degenerative valve disease, where the heart valves gradually thicken and stop sealing properly.
In cats: Murmurs often relate to changes in the heart muscle itself (a condition called cardiomyopathy).
In puppies and kittens: Soft murmurs are sometimes "innocent" and disappear by 4–6 months but persistent murmurs in young animals should always be investigated for congenital heart defects.
When your vet says your pet has a "Grade 3 murmur," they're describing how loud it is — not how serious it is. This is one of the most misunderstood parts of a heart murmur diagnosis, so let's be clear:
A louder murmur does not always mean a sicker pet.
Some pets have very loud (Grade 5) murmurs from relatively mild conditions, while others have quiet (Grade 2) murmurs hiding more significant disease. The grade tells us how loud — not how serious. That's why the next step matters more than the number.
This is the question we hear most often, and it's a fair one. Your pet is bouncing around, eating well, chasing the ball at Curl Curl. Why investigate?
The honest answer: pets are very good at hiding heart disease until it's advanced. By the time you can see symptoms, the disease has usually been progressing quietly for some time.
A stethoscope tells us a murmur exists. A heart ultrasound (echocardiogram) tells us why.
We use high-resolution imaging to look inside the chambers of the heart and check for enlargement. This matters because research shows that starting medication at the right stage — specifically, when the heart first begins to enlarge, can delay the onset of heart failure by up to 15 months in dogs.
That's 15 extra months of normal life. Walks, ball games, beach trips, family time.
Most heart murmurs can be completely investigated with an in-house ultrasound right here at Allambie Vet, and many pets are then comfortably managed by their regular vet, sometimes for years before anything changes.
Here's how we think about it:
We'll always be upfront about which step your pet actually needs.
This is one of the most common worries we hear, and it's worth addressing directly.
A heart ultrasound at Allambie Vet is a calm, low-stress experience for most pets. Here's what to expect:
For most dogs and cats, the hardest part of the visit is the car ride. Anxious or fractious pets may benefit from a mild calming medication beforehand, and in some cases, light sedation is the kindest option. We'll always talk you through what's right for your pet.
The single most useful tool you have at home is free, takes 30 seconds, and gives you genuine early warning of heart trouble. It's called the Resting Respiratory Rate (RRR).
How to do it:
The goal: under 30 breaths per minute.
Why it matters: a consistently rising RRR is often the earliest warning sign that fluid may be building up around the lungs — sometimes picked up days before you'd notice any visible symptoms. Many owners track theirs in a notes app once or twice a week.
If the number starts climbing, call us. This single habit has prevented countless emergency visits.
Northern Beaches pets lead active lives — chasing balls at Curl Curl, hiking Manly Dam, swimming at Clontarf or Forty Baskets — which actually helps us, because subtle changes in stamina and behaviour stand out more than they would in a less active pet.
Keep an eye out for:
None of these symptoms automatically mean heart disease, but if you notice them — especially in combination — it's worth a check.
A common worry is whether heart medications will make pets sleepy or "not themselves." The good news: modern cardiac medications, like pimobendan — are generally very well tolerated, and many dogs actually feel better on them because their heart is working more efficiently.
We'll always walk you through what to expect, what side effects to watch for, and what each medication is doing.
Cardiac diagnostics aren't cheap, and the gap between a routine vet visit and a referral hospital can feel like a cliff. The good news: an in-house heart ultrasound here is typically more affordable than a specialist-centre workup, and for most pets it gives us everything we need.
If your pet is insured, we're always happy to submit a pre-approval request to your insurer before going ahead — so you know exactly what's covered before any decisions are made.
We're happy to talk through what's involved and what's genuinely necessary for your pet — just ask.
If your pet has been diagnosed with a murmur and you live in Allambie Heights, Manly, Freshwater, Curl Curl, Dee Why, Brookvale, Balgowlah, Manly Vale, Frenchs Forest, Belrose, or Cromer, our team is here to provide the local, expert answers you need.
Whether you're after answers, reassurance, or a second opinion, we're here to support you and your family member every step of the way.
📞 (02) 9905 0505
📍 92 Allambie Rd, Allambie Heights NSW 2100
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