Heart Disease in Dogs: Causes, Symptoms, and Care

6 min read
6 min read

Updated - Dec 9th, 2022

Key Points

  • Age is one of the most common reasons why a dog may develop a heart condition, however, breed and genetics can also play a large role.
  • Lethargic behavior, change in appetite, and difficulty breathing are some indicators of heart disease.
  • If detected early, and treated with a healthy diet, exercise, and proper medication, dogs with heart disease can still live a happy, full life.

Heart disease in dogs can be a scary condition to navigate, however, if caught early, it can be managed with a good diet, medication, and exercise. Here, we’ll discuss common symptoms to look out for, prevention methods to implement, and most importantly, how you can work with your veterinarian to treat your dogs’ heart condition and better their quality of life. 

Bear in mind that “heart disease” is an umbrella term for different kinds of heart irregularities. These conditions may include mitral valve disease, dilated cardiomyopathy, canine valvular disease, arrhythmias, and pericardial disease, all of which affect the heart in different ways.


When it comes to treating heart disease in dogs, the sooner it is detected, the better the outcome. If your dog exhibits a number of the following symptoms, it’s worth checking in with your vet:

  • Lethargy or reduced activity
  • A decrease in appetite 
  • Abdominal swelling
  • Difficulty breathing or panting
  • Noticeable coughing and gagging
  • Fainting 
  • Weight loss 


There are many potential causes of heart disease in dogs, so it can be hard to put a finger on the exact culprit. Here are a few possible contributing factors:

  • Age: Heart disease is more likely to affect older dogs, however, it can affect middle-aged dogs as well.
  • Breed: Unfortunately, some breeds are more susceptible to heart disease than others. Some examples of large dogs that may be predisposed to heart disease include Great Danes, Irish Wolfhounds, Doberman Pinschers, and Boxers. Small breeds that may be predisposed to heart disease include Pomeranians, Cocker Spaniels, Toy Poodles, and Dachshunds.
  • Diet/weight: If your dog eats an unhealthy diet or is considered overweight, their lifestyle can eventually catch up to them and affect their heart health.
  • Heartworms: Heartworms in dogs can reduce blood flow and increase chances of heart failure. It’s important to get them treated as soon as possible to reduce the chances of heart disease and lasting cardiovascular damage.


If your veterinarian suspects your dog has heart disease, they may refer you to a veterinary cardiologist. A veterinary cardiologists can help you pinpoint the cause of your dog’s symptoms by conducting various exams such as: 

  • Blood and urine tests: A blood and urine test can help check for other health issues that might be affecting your dog.
  • Auscultation: Your vet uses a stethoscope to listen to your dog’s heart or other organs and detect any abnormalities.
  • Electrocardiogram (ECG or EKG): Using electrical signals, your vet can analyze your dog’s heart rate and identify irregularities.
  • Echocardiogram (or ultrasound): An ultrasound that uses waves to detect abnormalities in your dog’s heart chambers, which are used as the heart pumps blood.
  • Chest X-ray: A chest X-ray captures images of your dog’s organs with high visibility, allowing the vet to take a closer look.
  • Heartworm antigen test: To rule out the possibility of heartworm, your dog may have to undergo a heartworm test. 

Dogs typically suffer from two common heart conditions: mitral valve disease (MVI) or dilated cardiomyopathy (DCM). Mitral valve disease damages the mitral valve, which eventually causes fluid buildup in the lungs. Dilated cardiomyopathy causes the heart muscles to weaken, affecting the heart’s ability to pump blood. Although these are the most common, there could be other abnormalities – particularly with older or senior dogs


At the risk of sounding repetitive, we can’t stress enough the difference early intervention and treatment can make! Dogs with heart disease are often prescribed medications that help the heart work more efficiently or reduce fluid buildup. In more severe cases, surgery may be required to repair a damaged valve. Remember, every dog has different needs, so treatment plans can vary. Your vet will be your best advocate in figuring out how to preserve your dog’s long-term heart health.

In addition to medication, lifestyle changes can be incredibly impactful. From a nutritious, low-sodium diet, to carefully monitored exercise, to even introducing supplements like Vitamin B or taurine, these are just a few additional ways to support your pup’s heart health.


Veterinarian and author Dr. Jamie Whittenburg (DVM) explains, “The best way to begin preventing heart disease in dogs is thorough and responsible breeding, as most cases are genetic.” Genetic heart conditions, commonly referred to as congenital heart disease, are conditions pups are born with, and symptoms develop as they age. 

Dr. Whittenburg also says, “A high-quality diet should be fed at all times, and unhealthy treats and snacks should be kept to a minimum. There is an ongoing investigation regarding heart disease and grain-free and ‘boutique’ foods in dogs. Though the exact cause has yet to be determined, we do know there is a correlation between the two.” 

Dr. Sara Ochoa (DVM) is another certified veterinarian and author who shares additional insight on taking preventative measures, especially before symptoms worsen:

“For dogs that are prone to heart disease, starting them on a heart supplement can help extend their time until they show signs of heart issues or need heart medication. I have an 11-year-old schnoodle that has a mild heart murmur that I started on heart supplements when I first noticed her symptoms. She has not had to start additional medication other than her supplements for the past 2 years.” 

If you’re unsure what a good diet looks like for your dog, never hesitate to reach out to your vet for recommendations.

What to expect at the vet’s office 

If you suspect your dog may have heart disease, take them to the vet as soon as possible. There, the vet will examine your dog’s health and issue various tests such as bloodwork, echocardiogram, or EKG to find the cause and come up with the best treatment plan.

“Not all general practice vets will do all of these procedures,” says Dr. Ochoa. “They may refer you to a veterinary cardiologist, especially for the echocardiogram.” 

The bottom line

Simply put, the most effective way to treat your dog for heart disease is to work with your veterinarian and maintain a consistent treatment plan for your dog. Heart exams and blood work are two key methods that can help you narrow down the cause of their symptoms – and pinpoint what type of medication, procedure, and lifestyle changes they need to minimize their discomfort. 

So don’t wait – if you notice any possible heart issues in your dog, get them checked out as soon as possible! Our time with our pets is precious, and ensuring they get the best care possible helps them live a full and happy life.


Is heart disease preventable for dogs?

As of now, heart disease isn’t preventable. But with the right medication, diet, and supplements, you may be able to decrease the severity of your dog’s symptoms.

What foods can help with my dog’s heart health? 

Green vegetables, berries, and organic, unsalted meat are all beneficial for your dog as long as they’re given in moderation.

Is heart disease painful for dogs? 

Heart disease can certainly cause discomfort, though your dog may not immediately express their pain. That’s why it’s important to monitor for symptoms like a change in activity, diet, or sleeping schedule.

Did you know? 

  • During the preclinical phase, dogs often do not exhibit any visible signs of heart disease. 
  • If heart disease is caught early, dogs can still live a happy, healthy life. 
  • Canine heart disease is common, affecting approximately 8 million dogs in the U.S.

Shi-won Oh

Shi-won Oh

Shi-won is a copywriter and an enthusiastic dog aunt to Maltese and Shih Tzu puppies.
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