Is my dog’s breed at risk for heart disease?

Disclaimer: This article, its content, and its related references do not constitute veterinary advice and should not be considered a substitute for veterinary care. If your pet is showing any symptoms that could indicate a medical emergency, please seek immediate emergency care.

There are many types of diseases that can affect a dog’s heart muscle cells, chambers, valves, and blood vessels. Some types of heart disease are more prevalent in certain dog breeds than others, putting them at a higher risk. If you have a dog, read on to learn:

• What is heart disease?
• Is my dog at risk for heart disease?
• When should I talk to a vet about my dog’s risk of heart disease?

There are many dog breeds who are predisposed to dilated cardiomyopathy, degenerative valve disease, heart murmurs and arrhythmias, and genetic defects such as pulmonic or aortic stenosis. Breeds such as Cavalier King Charles spaniels, boxers, and German shepherds are at especially high risk for certain types of heart disease, though there are many other breeds that are also predisposed. Screening and early detection play an important role in preventing congestive heart failure and other complications of heart disease, so it’s important to get regular wellness checks with a veterinarian and diagnostic testing as recommended.

Cardiovascular disease, or heart disease, refers to any abnormality of the heart that impedes heart function. Heart disease in dogs can be congenital or acquired.

• Congenital heart disease: A heart condition present at birth
• Acquired heart disease: A heart issue that develops later in life

There are many different types of heart disease that can affect dogs.

What is a breed predisposition?

Many heart diseases in dogs have a large genetic component, or breed predisposition. This makes some dog breeds more at risk for certain kinds of heart problems compared to other breeds. However, any breed of dog can develop any type of cardiac condition, even if they’re not considered an at-risk breed.

There are many types of heart disease a dog can be born with or develop later in life. Some heart issues are more common than others, especially in certain breeds. Heart conditions in dogs can affect different parts of the heart’s muscle cells, chambers, valves, and blood vessels.

A dog’s heart has four chambers that briefly hold blood before the heart muscle contracts and the blood is pumped through valves between chambers. Blood enters the chambers on the right side of the heart then is pumped to the lungs where it’s oxygenated. From there, it enters the chambers on the left side of the heart and gets pumped to the rest of the body, providing the oxygen necessary for tissues to function. Heart valves keep the blood moving in one direction, preventing turbulent blood flow and blood moving backward through the heart, both of which can cause health issues.

The severity and nature of symptoms produced by different types of heart disease vary depending on which part of the heart is affected and how that part impacts the flow of blood to the heart and throughout the body. In addition, heart conditions that make the heart work harder than normal can lead to congestive heart failure, a life-threatening condition.

Degenerative mitral valve disease

Mitral valve disease describes any condition in dogs that affects the valve separating the two left chambers of the heart. If the mitral valve isn’t working properly, it leaks blood backward, causing the heart chamber to enlarge to accommodate the increase in blood volume.

Degenerative mitral valve disease is a common type of heart disease in which the mitral valve progressively thickens as a dog ages, interfering with the valve’s ability to properly open and close. This leads to some blood leaking backward into the left atrium instead of leaving the heart through the aortic valve to the rest of the body. Small-breed dogs that are middle-aged or older are at the highest risk for the condition. Dog breeds that are most at risk for degenerative mitral valve disease include:

• Cavalier King Charles spaniel
• Dachshund
• Cocker spaniel
• Miniature and toy poodle
• Shih tzu
• Chihuahua

Degenerative mitral valve disease is very common in Cavalier King Charles spaniels. Nearly all Cavalier King Charles spaniels will eventually develop the disease. Dogs with degenerative mitral valve disease are at risk for the disease progressing to congestive heart failure.

Dilated cardiomyopathy

Dilated cardiomyopathy (DCM) describes a condition in which the heart muscle loses tone, stretching out and growing thin over time. The thinner walls are weaker than normal and can no longer pump blood efficiently. As the disease progresses, the heart changes from a firm, strong, muscular organ into a balloon-like, loose and floppy globe. Giant- and large-breed dogs are more commonly affected, and some cases have a genetic component. Examples of commonly affected breeds include:

• Boxer
• Doberman pinscher
• Great Dane
• Irish wolfhound
• Saint Bernard
• Newfoundland dog
• Portuguese water dog

Many cases of DCM can’t be treated, and affected dogs typically develop congestive heart failure.

Abnormal heart rhythms

Abnormal heart rhythms, or arrhythmias, can affect dogs of any age, size, or breed. However, some specific types of arrhythmias affect certain dog breeds more than others.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an arrhythmia primarily seen in the right ventricle but which can also occur in other areas of the heart. ARVC can reduce blood flow to the body and also cause tachycardia, which is when the heart beats faster than normal but further decreases the efficiency of circulation. ARVC can also progress to a potentially fatal abnormal rhythm called ventricular fibrillation, in which the contractions of the heart muscle are no longer coordinated and do not push blood through the heart or to the body. ARVC is also known as “boxer cardiomyopathy” because boxers are the most common breed affected by the disease. Bulldogs and German shepherds are also genetically predisposed to forms of ventricular arrhythmia.

Sick sinus syndrome is another cardiac disease that affects the heart’s rhythm. In this condition, the sinus node that initiates a heartbeat doesn’t discharge an electrical impulse to contract the heart at regular intervals. Without this electrical impulse, the heart doesn’t beat. Often, the sinus node will start again or a different part of the heart will initiate a beat instead. Sick sinus syndrome causes a dog’s heart rate to be abnormally slow (bradycardia) and may also lead to periods when the heart beats too quickly (tachycardia), both of which can be dangerous. High-risk breeds for sick sinus syndrome include:

• West Highland white terrier
• Dachshund
• Miniature schnauzer
• Boxer
• Cocker spaniel

Congenital heart defects

There are a wide variety of birth defects that can affect a dog’s heart. Congenital cardiac defects in dogs can occur for a variety of reasons, including a genetic predisposition. However, they’re less common than acquired heart conditions.

Some breeds are predisposed to developing pulmonic stenosis, which describes an obstruction of blood flow from the heart to the lungs through the pulmonic valve. Breeds at risk for pulmonic stenosis include:

• English bulldog
• Boxer
• Beagle
• Terrier breeds

Aortic stenosis is a similar condition that occurs when blood flow out of the heart through the aortic valve is obstructed. Breeds with a genetic predisposition for aortic stenosis include:

• Golden retriever
• Boxer
• Rottweiler
• German shepherd
• Newfoundland dog

Since early detection is critical to managing many types of heart disease, there’s no need to wait until your dog is showing symptoms of heart disease to talk to a veterinarian. You can bring up any concerns at your yearly wellness exam, when the vet typically listens to your dog’s heart with a stethoscope. They may hear clues that a cardiac condition is present, such as a heart murmur or arrhythmia. “Regular checkups with a vet are important and may help catch heart conditions before clinical signs are observed at home,” explains Dr. Jo Myers, a veterinarian on the Vetster platform. “However, some dogs with heart disease will not have any abnormal findings during a physical examination. As a result, at-risk breeds or individuals experiencing symptoms of heart disease may require advanced diagnostic testing.”

If you’re concerned about your dog’s overall risk of cardiovascular disease based on their breed or lifestyle, a veterinary professional can help by answering questions, describing signs of heart disease, and offering advice about screening for heart conditions. An online virtual care appointment is an excellent tool to discuss your dog’s predisposition to heart disease.

What dog breed is most at risk for heart problems?

There are various dog breeds that are at a higher risk of heart disease. Large and giant breeds are more likely to develop dilated cardiomyopathy, while many smaller breeds are predisposed to degenerative mitral valve disease. Cavalier King Charles spaniels are very likely to develop degenerative mitral valve disease. Other breeds at risk for various heart conditions include boxers, German shepherds, cocker spaniels, Great Danes, and others.

What breeds of dog develop congestive heart failure?

Any dog can develop congestive heart failure. However, breeds that are predisposed to various heart conditions, such as degenerative mitral valve disease or dilated cardiomyopathy, have a higher risk. Breeds predisposed to these conditions include Cavalier King Charles spaniels, dachshunds, cocker spaniels, boxers, German shepherds, Great Danes, and others.

Is my dog at risk for heart disease?

While any dog can develop heart disease, certain breeds are predisposed to heart conditions such as dilated cardiomyopathy, degenerative mitral valve disease, and congenital heart defects such as aortic or pulmonic stenosis. It’s best to talk to a veterinarian to learn more about your individual dog’s risk of heart disease based on their breed, lifestyle, and underlying health conditions.