What is a heart murmur in dogs?

A heart murmur is an abnormal sound that can be heard when listening to your dog’s chest. Your vet will likely pick it up with a stethoscope during an examination.

It’s caused by turbulent blood flow within the heart which means the blood isn’t flowing as smoothly as it should. This then creates additional sounds beyond what you usually hear with a normal, healthy heartbeat.

Heart murmurs are graded on a scale from one to six, with grade one the mildest and grade six the most severe. Things like the volume, duration and timing of the abnormal sounds can help a vet determine the severity.

For some murmurs, there’s no immediate threat to a dog’s health. But for others it can mean more severe cardiac issues – this may require careful monitoring or treatment and medication.

What causes a heart murmur in dogs?

Heart murmurs can be caused by a range of underlying conditions, including:

• Valve abnormalities
• Congenital heart defects
• Issues with the heart muscle
• Anaemia
• Infection and fever
• Thickened chambers

Symptoms of a heart murmur in dogs                       

The heart murmur itself might not have noticeable signs, but the underlying cardiac condition may have some symptoms, such as:

• Coughing – especially during or after exercise
  
  
• Lethargy – noticeable decrease in energy levels
  
  
• Difficulty breathing – laboured or rapid breathing
  
  
• Fainting or collapsing – this can indicate poor blood circulation
  
  
• Reduced appetite – leading to weight loss
  
  
• Abdominal distension – swelling of the abdomen
  
  
• Blue or grey gums – indicating inadequate oxygenation
  
  
• Irregular heartbeat – may be observed by feeling the pulse
  
  
• Excessive panting – even in the absence of exercise
  
  

Remember, these symptoms aren’t exclusive to heart murmurs and can be a sign of other health conditions.

You can also monitor how quickly your dog breathes when resting. This helps you check any changes in heart function. Wait until your dog is asleep, then count how many times they breathe in and out in one minute (one cycle in and out = one breath). The average is 15-30 breaths a minute. Keep a daily record of your dog’s breathing so you can check for any increases – an increase in breathing rate can indicate an early warning of poor blood flow and fluid build-up in the lungs.

Always speak to your vet if you notice any of the above symptoms or have any concerns about your dog’s heath.

How is a heart murmur in dogs diagnosed?

You’ll need to take your dog to a vet to have a heart murmur diagnosed.

They will likely listen to your dog’s heart rate and then request some diagnostic tests. These may include an echocardiogram – or heart ultrasound – to help identify the severity of the heart murmur.

They may also carry out chest x-rays and blood tests to assess organ function and check for any other underlying conditions.

The cost of testing for a dog heart murmur in the UK can vary based on the test used by your vet, the prices at the practice and where you live.

What’s the treatment for a heart murmur in dogs?

Once your dog’s been diagnosed, the treatment focuses on managing the underlying cardiac condition and relieving the associated symptoms.

The treatment your vet decides on will factor in the grade of the heart murmur, the underlying cause, your dog’s breed and their health.

The different treatments and medications include:

Medications

• Diuretics can help reduce fluid build-up in the lungs which eases the stress on the heart.
  
  
• ACE inhibitors can dilate blood vessels which improve blood flow and reduce the strain on the heart.
  
  
• Inotropic agents can enhance the heart’s pumping ability which can improve its effectiveness.
  
  

Dietary management

• A low sodium diet can help manage fluid retention which is a common issue associated with heart murmurs.
  
  

Exercise and weight management

• Dogs with heart murmurs benefit from controlled exercise like lead walking. Any strenuous activities should be limited to prevent strain on the heart.
• Maintaining a healthy weight is extremely important as obesity can worsen cardiac issues.
  
  

Vet check-ups

• Regular visits to the vets are key to monitor your dog’s condition. They help your vet to adjust any medication based on how well it’s working and any changes to the murmur.
  
  
  

Will pet insurance cover a heart murmur in dogs?

Yes, pet insurance can cover the diagnostic and treatment costs associated with a newly detected heart murmur in dogs. But you likely won’t be covered if it’s a pre-existing condition. You’ll need to check your policy documents to see what your insurance covers.

Find out more about pet insurance options through Asda Money.