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Dilated Cardiomyopathy (DCM) - Big dogs with big hearts ❤️

Updated: Nov 9, 2022

The next most common heart disease in dogs is called dilated cardiomyopathy (DCM). Early, asymptomatic disease once again benefits from early medical treatment, so detection of this problem as early as possible is important. Unlike MVD, DCM affects larger breed dogs. Although any dog can potentially be affected, the most commonly affected breeds are the Doberman Pinscher, Great Danes, Irish Wolfhounds, Boxers, Newfoundlands, Scottish Deerhounds, and the Dogue de Bordeaux. Detection of DCM in the asymptomatic stage can be difficult; over half of dogs with early asymptomatic disease do not have a detectable heart murmur. This means that vets may need to screen for the disease using blood tests or by performing a heart ultrasound scan. Dogs with a family history of DCM or unexplained, sudden death, especially higher-risk breeds, should be prioritised for screening.

Kieran Borgeat BSc(Hons) BVSc MVetMed CertVC MRCVS DipACVIM DipECVIM-CA

Dilated Cardiomyopathy (DCM) is a disease that affects the heart muscle causing it to become weak and unable to pump blood as effectively, over time because of this weakness all of the heart chambers stretch and dilate.


Early signs of DCM usually include reduced ability to exercise, or collapse. This can either be due to the weakened heart muscle failing to pump, or abnormal heart rhythm (arrhythmia). This arrhythmia can cause fainting (usually during exercise or excitement) or even sudden death and so any arrhythmia identified should be investigated using echocardiography and ECG tests.


Eventually, as the disease progresses the circulation of blood slows so much that fluid leaks out of the blood vessels into the lungs (pulmonary oedema) and the abdomen (ascites). This is known as congestive heart failure. Unfortunately, dogs identified at this stage have a poor prognosis and significantly reduced life expectancy and as such early diagnosis and treatment are key to try and slow the progression of the disease.

Naomi Murdock BVetMed MRCVS


One of the ways that we can screen your dog to check if they have DCM is by a simple blood test. Measuring a substance in the blood called proBNP can help determine whether a dog is likely to have DCM, even in the asymptomatic stage when no symptoms will be present.


If your dog has a raised proBNP level we may recommend further tests including a heart scan (heart ultrasound) or an electrocardiogram (ECG) where we'll be able to look at their heart in more detail and check its rhythm.


By diagnosing and treating these diseases early, it’s possible to:

  • Slow the disease progression

  • Extend your dog’s symptom-free time by delaying the onset of heart failure

  • Improve your dog’s quality and length of life


At-risk dogs should have regular check-ups, at least once a year. Is your dog due a check-up?

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