Heart disease in dogs is often a silent and progressive condition, developing gradually until the signs become more obvious—and more urgent. Recognizing those early warning signs can significantly improve your dog’s comfort, treatment success, and longevity.

At Stack Veterinary Hospital in Syracuse, New York, we specialize in the early detection, diagnosis, and management of canine heart disease. Whether your dog has already been diagnosed or you’re noticing new symptoms, this guide is here to help you better understand what heart disease looks like and how to take action.

What Is Canine Heart Disease?

Canine heart disease refers to a variety of conditions that impair the heart’s ability to pump blood efficiently. Some forms are congenital (present at birth), but most are acquired over time, particularly in middle-aged or senior dogs.

Common Types of Heart Disease in Dogs

  • Mitral Valve Disease (MVD)
    One of the most common heart conditions in small breed dogs, MVD occurs when the mitral valve weakens and leaks.
    Learn more from PDSA
  • Dilated Cardiomyopathy (DCM)
    Often seen in large breeds like Dobermans and Great Danes, DCM causes the heart muscle to become thin and stretched, reducing its ability to pump effectively.
  • Pulmonary Hypertension
    High blood pressure in the lungs can strain the heart and reduce oxygen delivery. This is often secondary to other illnesses.
    Explore pulmonary hypertension in dogs – Today’s Veterinary Practice
  • Heartworm Disease
    Caused by parasitic worms spread by mosquitoes. It damages the heart and lungs over time but is preventable with consistent monthly medication.
  • Hemangiosarcoma
    A cancerous tumor that can affect the heart and cause sudden collapse or bleeding.
    More on hemangiosarcoma from Cornell University

What Causes Heart Disease in Dogs?

Breed Predisposition

Genetics play a big role. Some breeds are more prone to heart conditions than others.

Other Risk Factors

Early Signs of Heart Disease in Dogs

Early detection is critical. The earlier you recognize the signs, the more options your veterinarian has for managing the condition.

Read more about symptoms – Morris Animal Foundation

Symptoms to Watch For:

  • Persistent cough, especially at night or after light activity
  • Shortness of breath or labored breathing
  • Tiring easily on walks or during play
  • Fainting or collapsing (due to lack of blood flow)
  • Loss of appetite or gradual weight loss
  • Swollen belly (fluid buildup/ascites)
  • Increased thirst or urination
  • Restlessness at night

If you notice any of these signs—especially more than one—schedule a veterinary visit right away.

Diagnosing Heart Disease: What to Expect at the Vet

A proper diagnosis typically requires a combination of physical exams, imaging, and laboratory tests.

Learn more about heart disease diagnostics – Cummings School of Veterinary Medicine

Diagnostic Tools

  • Physical Exam
    Your vet may detect a heart murmur or irregular rhythm by listening with a stethoscope
  • X-rays
    Evaluate heart size, detect fluid in the lungs, and assess surrounding structures
  • Echocardiogram (Heart Ultrasound)
    Provides a detailed look at the heart’s anatomy and pumping function
    How dog echocardiograms work – Zoetis Petcare
  • Electrocardiogram (ECG or EKG)
    Detects abnormal electrical activity in the heart, such as arrhythmias
    Electrocardiogram explained – WagWalking
  • Blood Work
    Checks organ function and may include heart-specific markers

Treatment Options for Canine Heart Disease

While most heart disease is not curable, it is manageable—especially when caught early.

Medications

  • Diuretics: Help remove excess fluid
  • ACE Inhibitors: Reduce blood pressure and heart strain
  • Pimobendan: Improves heart muscle function
  • Antiarrhythmic medications: Regulate irregular heartbeats

Lifestyle and Diet

  • Low-sodium diet: Reduces fluid retention
  • Moderate, vet-guided exercise: Keeps circulation healthy without overloading the heart
  • Weight management: Essential to reduce cardiac workload

Advanced Interventions

  • Pacemaker placement: For dogs with severe arrhythmias
  • Heart valve surgery: Available at specialty centers in select cases

Your veterinarian will customize your dog’s treatment based on their diagnosis, symptoms, and overall health status.

Prevention and Early Intervention

What You Can Do Now

  • Start preventive heartworm medication if not already on one
  • Schedule yearly wellness exams, even if your dog seems healthy
  • Monitor subtle changes like reduced stamina, appetite, or coughing

For high-risk breeds, consider annual echocardiograms or breed-specific heart screenings starting in middle age.

When to Seek Immediate Veterinary Care

Call your veterinarian—or visit an emergency clinic—if you notice:

  • Sudden collapse or fainting
  • Open-mouth breathing or blue gums
  • Unrelenting coughing or inability to rest comfortably
  • Severe abdominal swelling or signs of pain

Stack Veterinary Hospital offers emergency and specialty cardiology care, including diagnostics, treatment, and ongoing support.

Contact Stack Veterinary Hospital if your dog is showing any signs of heart distress.

Compassionate Cardiology Care at Stack Veterinary Hospital

Heart disease can sound frightening—but with the right care, many dogs live full, happy lives. Our experienced team at Stack Veterinary Hospital is here to guide you through every step, from diagnosis to treatment and long-term management.

If you’re worried about your dog’s heart health, don’t wait. Request an appointment today.