The prevalence of heart disease is greater than 60% of dogs 7 years of age or older. The most common heart diseases encountered in dogs are degenerative valve disease (usually older small breeds) and dilated cardiomyopathy (usually large breeds).
A heart murmur is an abnormal sound (“whooshing”) heard when listening to the heart. A heart murmur is an indication of turbulent blood flow. The most common cause of a heart murmur is heart disease (however, there are other causes that may be benign).
Heart disease is a broad term that refers to any condition affecting the heart. The majority of animals with heart disease do not show outward signs/symptoms of their condition.
The tests used to diagnose/determine the cause of a heart murmur and the presence of heart disease include:
X-rays (of the chest) – this allows your veterinarian to evaluate the outline of the heart (to determine if there may be heart enlargement), the lungs, and the vessels of the heart and lungs. This is the best test to determine if there is abnormal fluid accumulation in or around the lungs.
Electrocardiogram (ECG) – this allows your veterinarian to determine the presence and type of arrhythmia (irregular heart beat).
Blood Pressure – Blood pressure is the measure of the force of blood pushing against blood vessel walls. It is important for your veterinarian to know whether your pet has high or low blood pressure.
Blood tests – there is no specific heart related marker on a standard blood test run by your veterinarian. There are specific cardiac biomarkers but are not run routinely. The utility of these biomarkers are still being explored.
Echocardiogram (ultrasound of the heart) – this is the most sensitive/specific test and allows your veterinarian to evaluate the heart structure and function. This test will help determine the cause of the heart murmur, type of heart disease, and stage of disease.
Heart failure/Congestive heart failure occurs with severe heart disease when the heart is eventually unable to keep up with the workload. This is the stage where symptoms are seen.
The most common symptoms associated with heart disease are:
- Difficult/labored breathing
- Exercise Intolerance
- Decreased appetite
- Bloated/distended abdomen
- Weight loss
Many times symptoms of heart disease are disregarded and believed to be related to aging, allergies, or other conditions. Although the symptoms of heart disease are not specific and can be associated with other problems, if your dog has been diagnosed with a heart murmur (or has already been diagnosed with heart disease) and any of these symptoms are present it is important to have them evaluated as soon as possible. If breathing difficulty is ever noticed they should be seen by your veterinarian or emergency facility immediately.
One symptom that you can easily monitor at home is their sleeping breathing rate. When they are in a deep sleep, watch as their chest/side goes out and then back in (this counts as one breath). Count the number of breaths per minute (you can count for 15 seconds and multiply by 4 to get breaths per minute). Keeping a daily log can help to track changes to the rate and allow for early detection of a potential problem. Any increases in the rate should be brought to the attention of your veterinarian. Sleeping respiratory rate in most dogs should be less than 30 breaths per minute.
The Las Vegas Veterinary Specialty Center has a dedicated Cardiology department with a board certified veterinary cardiologist. We have the staff and resources to give your pet the best care possible, and work with your family veterinarian to craft a treatment plan that is ideal for you and your pet.