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Dogs commonly get heart disease especially as they age.

If you have a dog with a heart murmur but no clinical signs of heart dysfunction, we may not recommend any treatment. We will however want you to monitor your pet at home and have your dog examined at least once a year at their yearly vaccination and health check.  

Animals with heart murmurs will have the murmur graded by your veterinarian each visit on a scale from 1-6. Once the murmur develops to a 3 out of six it is recommended to do a chest xray to look for any signs of cardiac remodeling.

Things to monitor in a healthy pet with a heart murmur.

  • Resting Heart Rate. The times the heart beats per minute (bpm). This varies depending on the size of the dog. Most dogs will have a heart rate of between 60 and 100 bpm when resting. Increases over time may be concerning and are good to mention to your veterinarian on you next visit.
  • Resting Respiratory Rate. The number of breaths in a minute when your dog is resting or asleep (RR). Normal dogs have an RR between 16 and 24. A RR above 30 may be a concern especially if your dog is showing more effort with it’s breathing.

  Get resting respiratory rate app from Apple store

  Get resting respiratory rate app from Google Play store

  • Exercise tolerance. Is your dog unable to walk as far as before? A decrease in exercise tolerance may be due to heart disease, not just a normal sign of ageing. 

What happens when the heart starts to fail?

The heart is a pump. When the heart starts to pump inefficiently the body has mechanisms to try to maintain the output of oxygenated blood. The body retains fluid in the blood, increases the blood pressure, increases the heart and respiratory rate and avoids exercise. When these compensatory mechanisms become overwhelmed, this leads to chronic (slow onset) or acute (sudden onset) heart failure. 

There are many types of heart disease. The most common disease we see is mitral valve insufficiency where one of the heart valves is leaking. This becomes progressively worse with age.

Heart medication and your dog.

When the heart is not functioning well your veterinarian can prescribe medication to help your dog live a happier, healthier life. There are a range of medications that may be prescribed. Medication doses should be adjusted at regular monitoring visits where you dog should also have regular blood tests and perhaps monitoring xrays. 

The medications do various things

  • Increase the strength of the heart beat
  • Control blood pressure
  • Control fluid retention
  • Stop the kidneys from over compensating and causing problems

Monitoring your pet with heart disease.

Dogs with heart disease respond best to treatment when carefully monitored. At Pittwater Animal Hospital we recommend examining your pet every three months if it is in heart medication. 

We recommend a twice yearly comprehensive blood test. These can be done through our discounted medication review system where a reminder is sent to your phone and the consultation and blood tests are done at a more affordable price.

If needed, urine tests may be performed.

Chest xrays can be taken to assess the heart-score of your dog. This measures the size of your dog’s heart and is an excellent monitoring tool. Hearts will enlarge and become more inefficient as the disease progresses, especially with inadequate medication. Chest xrays will also detect any congestion in the lung fields which will indicate a deterioration in your pet’s condition. 


 Heart score measures the size of the heart. 

Types of heart disease

There are many types of heart disease. The most common is valve failure but we see a variety of conditions including

  • Heartworm Disease. (More prevalent in Queensland)
  • Cardiomyopathy. Weakness of the heart muscle
  • Arrhythmia. A rhythm disturbance of the heart
  • Endocarditis. An infection of the heart valves
  • Pericardial Effusion. Fluid build up in the sac which surrounds the heart

These more unusual conditions may require input from a veterinary specialist. If we refer your pet they will assess the condition then communicate with us the best way to treat. Rechecks can often be done at Pittwater so your dog can be monitored locally.

  Make an Appointment with the Vet

or call us on 9913 7979

  Order Medication at the Vet

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