A heart murmur in cats can be alarming for any pet owner, but understanding what it means and how it affects your feline friend is crucial. A heart murmur is not a disease, but rather an abnormal heart sound that occurs when there is turbulent blood flow in the heart.
While some heart murmurs are harmless, others may indicate cardiac disease or other serious underlying conditions. In today’s blog, we will cover everything you need to know about heart murmurs in cats, from causes and symptoms to diagnosis and treatment.
What Is a Heart Murmur?
A heart murmur is an abnormal sound heard during the heartbeat cycle. Instead of the typical “lub-dub” sound, a murmur sounds like a whooshing or swishing noise. It occurs when blood flow in the heart becomes turbulent. Heart murmurs in cats are categorized into two types: innocent (non-threatening) and pathological (indicating heart disease).
Types of Heart Murmurs in Cats
- Innocent (Functional) Murmurs: These are benign murmurs that don’t indicate any underlying heart disease. An innocent heart murmur is often found in young kittens or healthy cats and typically resolve on their own.
- Pathological Murmurs: These are caused by structural abnormalities in the heart and can signal underlying heart disease such as hypertrophic cardiomyopathy or congenital heart defects.
How Are Heart Murmurs Detected?
Heart murmurs are typically detected during routine physical examinations when a veterinarian listens to your cat’s heart with a stethoscope (cardiac auscultation). The sound and intensity of the murmur will guide the veterinarian on the need for further diagnostic tests, such as echocardiograms, X-rays, and blood tests.
Causes of Heart Murmurs in Cats
- Congenital Heart Defects: Some cats are born with a congenital heart disease such as an atrial septal defect or a ventricular septal defect, which can cause heart murmurs. These congenital issues can interfere with normal blood flow, leading to turbulent sounds.
- Acquired Heart Conditions: Conditions like hypertrophic cardiomyopathy, the most common form of heart disease in cats, can develop over time and cause heart murmurs. Hypertrophic cardiomyopathy is a structural heart disease that leads to thickening of the heart muscle, which disrupts normal blood flow.
- Other Causes: Other conditions such as anemia, hyperthyroidism, or hypertension can also lead to the development of heart murmurs in cats.
Symptoms of Heart Murmurs in Cats
- Visible Signs to Watch For:
- Fatigue
- Difficulty breathing (dyspnea)
- Pale gums
- Rapid or shallow breathing
- Weight loss or poor appetite
- Silent Symptoms: In many cases, heart murmurs in cats do not show obvious symptoms, especially if they are mild. This is why regular vet check-ups are important for early detection of heart issues.
Diagnosis and Grading of Heart Murmurs
Heart murmurs are graded on a scale of 1 to 6 based on their intensity:
- Grade 1: Very soft murmur, barely audible.
- Grade 2: Soft but easily heard.
- Grade 3: Moderately loud.
- Grade 4: Loud murmur but no vibration of the chest wall.
- Grade 5: Very loud with chest vibration.
- Grade 6: The loudest heart murmur, which can be heard even without a stethoscope touching the chest wall.
Diagnostic Tests:
- Echocardiogram: A key tool in diagnosing heart murmurs, it provides an ultrasound image of the heart to determine if structural abnormalities are present.
- X-rays: Used to assess the size and shape of the heart.
- Blood Tests: Help rule out secondary conditions like hyperthyroidism or anemia, which can cause murmurs.
Treatment Options for Cats with Heart Murmurs
If your veterinarian detects a clinically significant heart murmur in your cat, there are several treatment options available:
- Medications: Depending on the cause, your veterinarian may prescribe medications such as beta-blockers or ACE inhibitors to help manage blood pressure and reduce strain on the heart.
- Lifestyle Changes: Maintaining a healthy weight, minimizing stress, and providing a balanced diet are essential steps to manage heart murmurs. Some cats may need a specialized diet to support heart health.
- Surgery: In cases where a congenital heart defect like a septal defect is causing the murmur, surgical intervention may be necessary.
Prognosis and Life Expectancy
The prognosis for a cat with a heart murmur depends largely on the underlying cause.
- Mild Murmurs: Cats with innocent murmurs or mild heart conditions can live long, healthy lives with regular monitoring.
- Severe Cases: Cats with significant heart disease, such as congestive heart failure, may have a shorter life expectancy and require ongoing treatment and veterinary care.
Preventive Care and Monitoring
- Regular Veterinary Visits: Routine check-ups are essential for monitoring your cat’s heart health, especially if a murmur has been detected. Early detection of any changes can improve the chances of managing the condition effectively.
- At-Home Monitoring: Keep an eye on your cat’s behavior, appetite, and activity levels. Any changes in breathing patterns, lethargy, or sudden weight loss should be reported to your vet immediately.
Monitoring Heart Murmurs Over Time
Even if your cat has been diagnosed with an innocent murmur, periodic monitoring is essential. Heart murmurs in cats can change over time, and what may initially seem benign could later indicate a more serious issue.
Heart Murmurs in Kittens vs. Adult Cats
- Young Kittens: Innocent heart murmurs are commonly found in young kittens and often disappear as they grow older.
- Adult Cats: In adult cats, heart murmurs are more likely to be associated with underlying heart conditions, so they require closer monitoring and, in some cases, treatment.
Signs of Heart Failure
In severe cases, heart murmurs can lead to congestive heart failure. Clinical signs of heart failure in cats include:
- Coughing
- Difficulty breathing
- Fainting or collapsing
- Swollen abdomen due to fluid buildup
If any of these symptoms are observed, it’s critical to seek immediate veterinary attention.
The Importance of Early Detection
Detecting a heart murmur early allows for better management and treatment. Regular veterinary check-ups, especially as your cat ages, are vital for maintaining their overall heart health.
A heart murmur in cats may be incidental or a sign of an underlying heart condition. While some murmurs are benign and harmless, others require medical attention and ongoing care. Understanding the causes, symptoms, and treatment options for feline heart murmurs can help you make informed decisions about your cat’s health. If you suspect your cat has a heart murmur or notice any concerning symptoms, contact your veterinarian for a thorough evaluation.
At Modern Vet, we specialize in comprehensive veterinary care, offering diagnostic tests, treatment options, and ongoing monitoring for heart murmurs and other feline health conditions. Don’t hesitate to reach out to ensure your cat receives the best care possible.
