Both cats and dogs can be susceptible to heart disease at any age and it is important to note changes such as coughing, exercise intolerance, or lethargy. However, the rate of cardiovascular problems does increase with age.
The most common type of heart disease in both dogs and cats is valvular disease. In valvular disease, the valves that separate the chambers of the heart do not close completely and this allows a backflow of blood with each beat of the heart- making it a much less effective pump.
Other types of heart disease affect the heart muscle itself. In dogs, dilated cardiomyopathy (DCM) can occur. In DCM the heart becomes larger and the muscle is stretched thin. The thin muscle walls contract less efficiently. In cats, hypertrophic cardiomyopathy (HCM) can occur in which the heart muscle becomes thicker. The muscle is so thick that it also cannot effectively contract and push the blood through the heart and to the lungs and body.
Cats may also get DCM and restrictive cardiomyopathy (RCM) as well. Heart diseases such as these can lead to congestive heart failure in which fluid builds up in either the lungs or abdomen due to pressure backflow of blood from the malfunctioning heart. This can make it difficult for the pet to breath and cause coughing if the fluid is in the lungs and bloating/fluid retention in the abdomen.
In addition to diseases of the heart itself, older patients are more susceptible to diseases of the vessels as well. Hypertension is a common secondary disease to hyperthyroidism in cats, kidney disease, and some metabolic diseases. Cardiovascular diseases can make the pet more susceptible to thromboembolism (blood clots) that can go anywhere in the body causing problems such as stroke.
Diagnosis: Dr. Claus and Dr. Evert will listen to your pet’s heart and lungs at every exam. If they hear a heart murmur or muffled lung sounds they may recommend a more complete cardiac work-up, which includes chest x-rays, an electrocardiogram (ECG), and an echocardiogram (ultrasound of the heart). Bloodwork may also be recommended to check for changes associated with trauma to the heart muscle or other changes that may affect the cardiovascular system. A measurement of blood pressure may also be recommended if signs of it are noted.
Treatment: Based on the results of the above tests medications may be recommended, or it may be recommended that the patient just be monitored for progression of disease.
If you think your dog or cat is experiencing cardiac symptoms, call and schedule an appointment right away!
Dr. Dawn Evert is the Associate DVM at Claus Paws Animal Hospital. Cardiology and client education are of special interest to her, and she contributed this piece for the website. Thank you, Dr. Evert!