Spending quality time with our dogs—whether on long walks, chasing a ball at the park, or relaxing on the sofa—is one of the greatest joys of being a pet parent. But as our furry companions grow older, those joyful moments may also reveal subtle changes in their health. Perhaps your once-energetic pup now slows down during walks, coughs after exercise, or breathes more heavily at rest. While it’s tempting to dismiss these signs as “normal aging,” they may be early symptoms of heart disease.

Heart disease in dogs is more common than many realize. Studies show that 10% of dogs in the United States will develop some form of heart disease, with the risk increasing significantly in senior dogs over seven years old. For small breeds, one of the most common culprits is mitral valve disease (MVD), while larger breeds are more likely to suffer from dilated cardiomyopathy (DCM), a condition affecting the heart muscle. Regardless of breed or size, early detection and proactive prevention are key to protecting your dog’s heart health.

👉 American Kennel Club: Heart Disease in Dogs provides a reliable overview of canine cardiac conditions.

Understanding Heart Disease in Dogs

Just like in humans, heart disease in dogs can result from valve problems, muscle weakness, or other degenerative changes in the cardiovascular system. Mitral valve disease, which affects the valves that keep blood flowing in the right direction, accounts for up to 75% of heart disease cases in dogs. When the valves weaken or misalign, blood leaks backward into the heart instead of being pumped to the body, leading to murmurs, fluid buildup, and eventually congestive heart failure (CHF).

On the other hand, heart muscle disease (such as DCM) weakens the pumping action of the heart, reducing circulation and oxygen supply. Both conditions progress slowly, meaning your dog may appear “normal” for years before showing noticeable signs. That’s why prevention, lifestyle adjustments, and regular vet visits matter so much.

Preventing Heart Disease in Dogs: What Every Pet Parent Should Know

Heart disease is not always preventable—some dogs are genetically predisposed. However, there are many steps you can take to reduce your dog’s risk and slow the progression of disease.

1. Keep Your Dog at a Healthy Weight

Obesity is one of the leading contributors to heart disease in dogs. Extra pounds put unnecessary strain on the heart, blood vessels, and lungs. Maintaining your dog’s ideal weight through a balanced diet and portion control is one of the most effective ways to prevent heart complications.

👉 The WSAVA Global Nutrition Guidelines offer excellent advice on portion sizes and weight management.

2. Choose a Heart-Healthy Diet

Nutrition plays a powerful role in heart health. Dogs with or at risk of heart disease benefit from：

• Low-sodium diets to reduce fluid retention and ease heart strain

• Omega-3 fatty acids (from fish oil) to decrease inflammation and support heart function

• High-quality proteins to maintain muscle strength

• Avoiding highly processed treats that contribute to obesity and hypertension

If your dog has been diagnosed with early heart disease, your veterinarian may recommend a prescription cardiac diet formulated to support cardiovascular health.

3. Prioritize Regular Exercise—But in Moderation

Exercise is essential for maintaining cardiovascular fitness, but balance is key. High-intensity activity may strain a weakened heart, while inactivity can worsen obesity and muscle loss. Aim for gentle, consistent activity—short daily walks, light playtime, or swimming (for dogs that enjoy it) are great options. Always monitor for signs of fatigue such as coughing, heavy panting, or slowing down.

4. Schedule Regular Veterinary Checkups

Early detection is your best defense against heart disease. Annual vet visits should become bi-annual visits once your dog reaches senior age (7+ years). During these checkups, your vet may perform:

• A physical exam to detect murmurs

• Chest X-rays to evaluate heart size and lung condition

• Echocardiograms (ultrasound of the heart) for detailed assessment

• Blood and urine tests to check organ health

Catching heart disease early often means treatment can begin before symptoms escalate.

5. Prevent Heartworm Disease

Heartworms can physically clog the heart and blood vessels, causing right-sided heart failure. Fortunately, monthly heartworm preventives are widely available and highly effective. Skipping doses puts your dog at serious risk, especially in warmer climates where mosquitoes thrive.

👉 Learn more from the American Heartworm Society.

Living with a Dog Diagnosed with Heart Disease

If your dog is already showing signs of heart disease—such as persistent coughing, exercise intolerance, or fainting spells—don’t lose hope. With proper treatment and care, many dogs live for years after diagnosis. Medications such as diuretics, ACE inhibitors, beta-blockers, and pimobendan can significantly improve quality of life. Lifestyle adjustments, stress reduction, and a carefully monitored diet make a big difference too.

Remember, heart disease is not an immediate death sentence. With vigilance, routine vet care, and a supportive environment, your dog can continue enjoying a comfortable, loving life.

FAQ: Preventing and Managing Heart Disease in Dogs

Q: At what age should I start worrying about heart disease in my dog?

Most cases appear in dogs over 7 years old, but some breeds (like Cavalier King Charles Spaniels) may develop symptoms earlier.

Q: What’s the most common sign of heart disease in dogs?

A persistent cough—especially at night or after exercise—is often the first sign owners notice.

Q: Can diet really prevent heart disease?

Diet alone won’t prevent genetic heart disease, but a balanced, low-sodium, nutrient-rich diet helps reduce risk factors like obesity and high blood pressure.

Q: Should I restrict exercise if my dog has early heart disease?

Not necessarily. Controlled, moderate exercise is encouraged, but avoid strenuous activity. Consult your vet for a tailored exercise plan.

Q: How important is heartworm prevention?

Critical. Heartworm disease is entirely preventable but extremely damaging once contracted. Monthly prevention is non-negotiable.