February is often associated with heart symbols, but it is also an opportunity for veterinarians to spread awareness about pet heart health. Nearly 10% of all dogs and a significant number of cats in the United States live with some form of cardiac disease. Because our patients cannot tell us when they feel off in their chest or experience heaviness in their breathing, early detection relies entirely on clinical screening and observant pet owners.
The reality of heart disease in pets is that it’s often a slow, quiet progression. By the time a pet shows obvious signs of distress, the disease is often advanced. However, with modern diagnostic tools and early intervention, many of these conditions can be managed effectively for years.
Dog Heart Disease
When we discuss dog heart health, we generally focus on structural changes. Unlike humans, dogs rarely suffer from “heart attacks” caused by blocked arteries. Instead, their issues are usually related to the valves or the muscle itself.
Degenerative Valve Disease
Degenerative Valve Disease is the most common form of dog heart disease, particularly in small to medium-sized breeds such as Cavalier King Charles Spaniels, Chihuahuas, and terriers. Over time, the mitral valve—the “door” that ensures blood flows in one direction from the top chamber to the bottom chamber on the left side of the heart—begins to thicken and fails to seal properly.
If your veterinarian mentions a “heart murmur,” they could be hearing the sound of blood leaking backward through that valve. A murmur is a clinical finding that warrants further investigation, typically an echocardiogram, to determine whether the heart is enlarging to compensate for the leak.
Dilated Cardiomyopathy (DCM)
In larger breeds, such as Doberman Pinschers, Great Danes, and Boxers, the concern is often the integrity of the heart muscle. Dilated Cardiomyopathy (DCM) causes the heart walls to become thin and weak, diminishing the heart’s ability to pump blood effectively to the rest of the body. Because this affects the “pump” directly, it can lead to exercise intolerance and fluid backup..
Cat Heart Disease
Cats present a unique diagnostic challenge. While dogs often provide clues like a persistent cough or a notable heart murmur, cat heart disease is notoriously subtle. Not all cats with heart disease have murmurs, and not all cats with murmurs have heart disease. This makes the diagnosis of heart disease in cats even more challenging.
The most frequent diagnosis in felines is Hypertrophic Cardiomyopathy (HCM). In this condition, the heart muscle becomes abnormally thick, which prevents the chambers from filling with an adequate volume of blood.
The most difficult aspect of feline cardiology is that many cats with significant HCM do not have a heart murmur. They may appear perfectly healthy until they experience sudden respiratory distress or a painful blood clot (thromboembolism). Because cats hide their symptoms so effectively, screening is essential—especially for at-risk breeds like Maine Coons, Ragdolls, and Sphynxs.
Red Flags: What to Watch for at Home
Early intervention depends on identifying subtle shifts in behavior or physiology. If you notice any of the following, a cardiac evaluation should be considered:
- Resting Respiratory Rate: This is the single most important metric you can track at home. When your pet is sound asleep, count how many times their chest rises and falls in one minute. A healthy pet should have a rate under 30 breaths per minute. A consistent rise in this number is often the first sign of impending heart failure.
- Reduced Stamina: If a dog that usually anticipates a walk suddenly resists going or sits down after a short distance, it is rarely just “getting older.” It is often a sign of decreased cardiac function.
- Fainting or “Wobbling”: Brief episodes of collapse (syncope) can occur during excitement or exercise. These are often mistaken for seizures but are frequently caused by an irregular heart rhythm or a sudden drop in blood pressure.
- The “Cardiac Cough”: In dogs, a chronic, hacking cough—particularly at night or when first getting up—can be a sign that an enlarged heart is pressing on the airway.
The Path to Management
When a murmur or an irregular rhythm is detected, the next step is typically a referral for an echocardiogram (a specialized heart ultrasound). This allows us to see the heart’s internal structures and measure its function in real-time.
The field of veterinary cardiology has advanced to a point where a heart diagnosis is no longer a terminal endpoint. We have access to sophisticated medications that can significantly delay the onset of congestive heart failure. The goal is to maintain a high quality of life, keeping pets comfortable and active for as long as possible.
Practical Steps for Pet Owners
This February, take a proactive approach to your pet’s cardiac health:
- Prioritize the Stethoscope: Ensure your pet has a thorough physical exam at least once a year. The stethoscope remains the most effective front-line screening tool.
- Monitor Sleeping Breathing Rates: Establish a baseline for your pet’s resting respiratory rate while they are healthy so you can easily spot changes.
- Investigate Murmurs Promptly: If a murmur is found, early staging allows for more precise treatment and a better long-term prognosis.
Pet Heart Health Awareness Month isn’t about the fear of a diagnosis; it’s about the power of early detection. When we understand the rhythm of our pets’ lives, we can act while time is still on our side.