Heart Diseases and Murmur in Cats and Dogs: Night Coughing, Shortness of Breath, and Early Diagnosis

01What is a Heart Murmur? The Difference Between Innocent and Pathologic Murmurs

Listening to the chest with a stethoscope (auscultation) by veterinarians during routine examinations provides invaluable data about the health of the heart. When a healthy heart is working, the opening and closing sounds of the valves are heard clearly as a "lub-dub". However, when the heart valves do not close completely or when there is an anatomical deterioration in the heart muscle, the blood deviates from its normal flow path and creates turbulence. The reflection of this turbulence heard through the stethoscope, resembling a "lub-shh-dub" sound, is called a "heart murmur".

A heart murmur in dogs may not always be a harbinger of a fatal disease. Mild "innocent murmurs" heard especially in puppies and kittens under 6 months of age usually disappear on their own as the animal grows. However, murmurs that suddenly appear in adult or older (geriatric) pets are pathologic. This situation indicates that blood is flowing backward (leaking) in the anatomical structure of the heart or there is a narrowing in the vessels. Although the grade of the murmur (graded from 1 to 6) provides information about the severity of the disease, it is a medical necessity to always resort to advanced imaging techniques for a definitive diagnosis.

03A Life-Saving Test at Home: How to Count the Sleeping Respiratory Rate (SRR)?

The most reliable way at home to understand whether your pet is at risk of heart failure or whether the heart medications they are using are working is the Sleeping Respiratory Rate (SRR) test. When fluid begins to accumulate in the lungs (edema), the animal starts breathing much faster even in its sleep to get oxygen. To perform the SRR test correctly, the following steps should be followed:

• Moment of Deep Sleep: Quietly approach your friend when they are in a completely deep sleep (a calm moment when they are not dreaming).
• Chest Movement: The rising and falling of the rib cage once is counted as "1 breath".
• Time Tracking: Using a stopwatch, count the breaths for exactly 1 minute (60 seconds).
• Critical Threshold Value: The sleeping respiratory rate of a healthy cat or dog in deep sleep should be under 30 breaths per minute. If this number goes above 30 per minute for a few consecutive days or reaches 40 while resting, the risk of pulmonary edema due to heart failure is quite high, and a clinic should be consulted without wasting time.

04Advanced Diagnosis in Heart Disease: ECHO, X-Ray, and NT-proBNP Test

Although listening with a stethoscope (auscultation) makes the presence of the disease felt, veterinary echocardiography devices come into play to determine the stage of the disease and which medication should be used.

Echocardiography (Heart Ultrasound) shows the dimensions of the heart chambers, muscle thickness (which is the gold standard in diagnosing feline heart enlargement HCM), and the amount of blood leaking from the valves instantly and in color (Doppler). A chest x-ray, on the other hand, clearly reveals whether the general silhouette of the heart has enlarged and the fluid accumulation (edema) in the lungs that triggers the night coughing picture in dogs.

The NT-proBNP blood test, which comes into play in current cardiology approaches, is a very sensitive biomarker showing how stretched and stressed the heart muscle is. Especially in cats that are difficult to examine under stress, it allows hidden heart diseases to be detected at the cellular level before presenting clinical symptoms.

05Living Environment and Exercise Management in Cats and Dogs with Heart Disease

After a cardiological diagnosis is made, in addition to medical treatment (medications), indoor living standards must also be rearranged in a way that will not tire the heart:

• Temperature and Humidity Control: Heart patients lose their tolerance to heat. During the highly humid summer months of Mersin, it must be ensured that your friend always rests in air-conditioned or well-ventilated cool areas.
• Exercise Restriction: Sudden strenuous activities that abruptly raise the heart rate, such as playing fetch, long runs, or going up and down stairs, should be restricted. Walks should be kept short and at a mild pace in the cool of the evening rather than during hot hours.
• Diet Modification: Sodium (salt) consumption must be restricted in heart patients. A transition should be made to physician-recommended "Cardiac" clinical diet foods enriched with Omega-3 (EPA/DHA), Taurine, and L-Carnitine, which support the heart muscle.
• Stress Management: Excitement, fear, and anxiety accelerate the pulse and put an extra load on the heart. The noise level in the house should be lowered, and sudden changes should be avoided.

06Cardiological Follow-up and Appointment Planning in Mezitli, Mersin

Since heart diseases progress insidiously, catching them in the early stages is the most critical factor in treatment success. As Mersin Anka Veterinary Clinic in Mezitli, Mersin, we approach heart health with great sensitivity in the routine health screenings of our patients, especially those over 7 years old.

For our friends who come to our clinic with complaints of fatigue, fainting, or coughing, we create a comprehensive cardiological profile using digital x-rays, advanced ultrasonography devices, and NT-proBNP screenings in our laboratory and imaging department. Within the framework of the geriatric care protocols applied to preserve the comfort of our older friends, we stage the disease according to ACVIM standards and apply personalized medical treatments. We aim to keep our patients' quality of life at the highest level by monitoring heart functions with regular ECHO follow-ups within the scope of Mezitli veterinary services.

Frequently Asked Questions