Heart Disease in Dogs Explained

Heart disease in dogs can sound worrying, but many dogs with heart conditions can continue to enjoy a good quality of life with the right care, monitoring and treatment. Understanding the early signs, knowing when to contact your veterinary surgeon, and learning how prescription heart medications can help are all important steps for dog owners.

At Vetscriptions, we know that hearing your dog has a heart problem can feel overwhelming. Our aim is to help make things clearer, so you can feel more confident about what heart disease in dogs means and how treatment may support your pet.

This article is intended for general guidance only and should not replace professional veterinary advice. If your pet is unwell or showing concerning symptoms, please contact your veterinary surgeon.

What is heart disease in dogs?

Heart disease in dogs refers to conditions that affect how well the heart works. The heart’s job is to pump blood around the body, delivering oxygen and nutrients to vital organs and tissues. If the heart is not working properly, fluid can build up, circulation may become less efficient, and your dog may start to show signs of illness.

Some heart conditions are present from birth, while others develop gradually as dogs get older. In many cases, heart disease progresses slowly, which means early changes can be easy to miss at home.

Common types of heart disease in dogs

Mitral valve disease

Mitral valve disease is one of the most common heart conditions seen in dogs, especially in older small breed dogs. The mitral valve sits between two chambers on the left side of the heart. Over time, it can become thickened and leaky, allowing blood to flow backwards instead of moving efficiently forwards.

This can lead to a heart murmur and, in some dogs, eventually congestive heart failure. Breeds such as Cavalier King Charles Spaniels are particularly prone to this condition.

Dilated cardiomyopathy

Dilated cardiomyopathy, often shortened to DCM, is a disease where the heart muscle becomes weak and enlarged. This means the heart cannot pump blood as effectively as it should. It is more commonly seen in larger breeds, such as Dobermanns, Boxers and Great Danes, although it can affect other dogs too.

Congenital heart disease

Congenital heart disease means a dog is born with a heart abnormality. These problems may involve the heart valves, blood vessels or the walls between the chambers of the heart. Some congenital heart issues are mild, while others need prompt veterinary attention.

Arrhythmias

Arrhythmias are abnormal heart rhythms. The heart may beat too fast, too slowly or irregularly. Some arrhythmias cause few obvious symptoms, while others can lead to weakness, collapse or reduced exercise tolerance.

Signs of heart disease in dogs

The symptoms of heart disease can vary depending on the type of condition and how advanced it is. Some dogs show very mild signs at first, while others become unwell more quickly.

Common signs to watch for include:

• Coughing, especially at night or after exercise
• Breathing more quickly than normal when resting
• Reduced energy or reluctance to exercise
• Tiring more easily on walks
• Weakness or collapse
• Loss of appetite
• Weight loss
• A swollen tummy due to fluid build-up
• Restlessness, particularly at night

If your dog develops sudden breathing difficulty, collapses, or seems very distressed, contact a veterinary surgeon urgently.

How heart disease is diagnosed

Heart disease is usually suspected after a veterinary examination. Your vet may hear a heart murmur, detect an irregular heartbeat, or notice signs such as increased breathing effort.

To understand the condition more fully, your veterinary surgeon may recommend tests such as:

• Chest X-rays to look at the size of the heart and check for fluid on the lungs
• An ultrasound scan of the heart, known as an echocardiogram
• An ECG to assess the heart rhythm
• Blood pressure measurement
• Blood tests to check overall health and organ function

These tests help your vet decide whether treatment is needed, which medications may be most suitable, and how often your dog should be monitored.

Treatment for heart disease in dogs

Treatment depends on the type of heart disease, how severe it is, and whether your dog has developed signs of heart failure. Some dogs need regular monitoring before any medication is started, while others benefit from treatment as soon as the diagnosis is confirmed.

Prescription heart medication

Many dogs with heart disease are treated with prescription medication to support heart function, reduce fluid build-up, and improve comfort. Common types of heart medication may include:

• Drugs that help the heart pump more effectively
• Diuretics, which help remove excess fluid from the body
• Medications that relax blood vessels and reduce strain on the heart
• Treatments to control abnormal heart rhythms

Your veterinary surgeon will explain which medicine your dog needs, how often it should be given, and whether follow-up checks are required. It is very important to give heart medication exactly as prescribed and not to stop treatment suddenly unless your vet advises you to do so.

If your dog has been prescribed ongoing treatment, you can browse our dog heart products and dog prescription products. We also provide practical guidance on how to order a prescription medicine and answer common questions in our prescription FAQs.

Monitoring and check-ups

Dogs with heart disease often need regular rechecks, even if they seem well at home. Your vet may want to monitor:

• Breathing rate
• Weight and body condition
• Kidney function and electrolytes through blood tests
• Changes in coughing or exercise tolerance
• Response to medication

This helps ensure the treatment plan remains safe and effective over time.

Lifestyle support

Alongside medication, a few simple adjustments at home may help support a dog with heart disease:

• Keep exercise gentle and consistent, based on your vet’s advice
• Avoid overexertion, especially in hot weather
• Maintain a healthy body weight
• Give all medications at the correct times
• Watch for changes in breathing, appetite or energy levels

Some dogs may also benefit from nutritional support or supplements, but these should only be used after checking with your veterinary surgeon, particularly if your dog is taking prescribed medication. If your vet recommends additional support, you may wish to explore our dog supplements or premium supplements range.

Can heart disease in dogs be cured?

In many cases, heart disease cannot be completely cured, but it can often be managed successfully. The aim of treatment is usually to slow progression, control symptoms and maintain a good quality of life for as long as possible.

Some dogs live comfortably for months or even years after diagnosis, particularly when heart disease is detected early and treatment is started at the right time. Regular monitoring and good communication with your veterinary practice are key.

When should you contact your veterinary surgeon?

You should arrange a veterinary appointment if your dog develops:

• A new cough or a cough that is getting worse
• Reduced stamina or reluctance to exercise
• Faster breathing when asleep or resting
• Episodes of weakness or collapse
• A swollen abdomen
• Poor appetite or unexplained weight loss

If your dog has already been diagnosed with heart disease, contact your vet promptly if symptoms change or medication seems less effective.

Understanding prescriptions and ordering medication

If your vet prescribes heart medication for your dog, you may be able to order it online once you have a valid prescription. We aim to make that process straightforward and reliable for UK pet owners. You can also complete our animal health form if needed as part of your order.

For general support with ordering, delivery or prescriptions, you can visit our contact page or read more about postage and delivery. We are committed to supplying genuine veterinary medicines responsibly, helping pet owners access ongoing treatment conveniently and affordably.

Supporting your dog with confidence

A diagnosis of heart disease can feel unsettling, but many dogs continue to enjoy happy, comfortable lives with the right treatment plan. Learning the signs, attending regular check-ups, and giving prescribed medication correctly can make a real difference to your dog’s wellbeing.

At Vetscriptions, we are here to help you understand your pet’s treatment options and access prescribed medication responsibly. If your dog has been diagnosed with a heart condition, you can explore our dog heart products, browse our wider dog collection, or speak to your veterinary surgeon for personalised advice.

If you would like to learn more about who we are and how we support pet owners across the UK, please visit our About Us page. As always, if you are worried about your dog’s breathing, energy levels or general health, please contact your veterinary practice without delay.