The heart of the matter: Cardiac disease in companion animals

Cardiovascular disease is an all-too-common condition in our companion animals. As many as 10 percent of adult dogs and cats have underlying cardiac issues, and this increases to 20-30 percent as they reach senior status. There are numerous types of heart disease, and heart disease can develop at any and all stages of life.

Congenital heart defects are problems that puppies and kittens are born with. Some congenital defects include abnormalities in the development of valvular structures and development of the heart muscle itself. These defects can often be detected on initial exam. If an abnormality is found during a routine puppy or kitten exam, early treatment, including placement of a stent or other surgical intervention, may provide long-term management or, in some cases, a cure. Your veterinarian may detect a heart murmur as early as six weeks. Often these murmurs resolve within a few weeks, but occasionally they become more intense over time. In this case, further diagnostic testing would be indicated to rule out an underlying defect. Diagnostics would include thoracic radiographs (X-rays), an echocardiogram (ultrasound of the heart) and likely an electrocardiogram (EKG). Puppies and kittens with congenital heart defects are often “unthrifty” and do not gain weight appropriately, and they may not be as playful as their litter mates. Be on the lookout for this when choosing a companion.

There are also many forms of acquired heart disease, including but not limited to valvular disease, dilated cardiomyopathy, acquired hypertrophic cardiomyopathy, hypertension (high blood pressure) and arrhythmias (abnormal cardiac rhythm). While we do not typically see cardiovascular disease secondary to high cholesterol or poor diet in dogs and cats as we do in people, cardiac problems may be secondary to other types of systemic illness, such as hyperthyroidism, hypertension, malnourishment or even heartworm disease.

Throughout life, biannual wellness exams and lab testing allow your veterinarian to detect changes that could indicate a problem. They will be evaluating your pet for heart murmurs, arrhythmias and changes in their pulse quality, which can all indicate underlying cardiac disease. If any of these changes are detected, further testing would likely be recommended. This would include a baseline EKG, echocardiogram and radiographs. They may also check your pet’s blood pressure and full bloodwork, including a complete blood count and chemistry screen and a heartworm test. In addition, your veterinarian can test for cardiac biomarkers (proBNP), which are expressed in patients that have changes to their cardiac muscle. An increase in this marker indicates abnormal stretching of the cardiac muscle and, likely, significant cardiac disease. Routine bloodwork can also pick up diseases, such as hyperthyroidism and heartworm disease, which can cause significant cardiovascular problems if left uncontrolled.

Between visits to your veterinarian, it is important to be on the lookout for signs of changes in cardiac function. This would include changes in activity level, changes in respiratory rate or effort, weakness or collapse, changes in appetite and coughing. These changes are often attributed to the aging process, and that a pet is “slowing down” as he or she gets older. However, there may be more than meets the eye. Be sure to mention any changes to your veterinarian. By the time a pet is coughing due to underlying heart disease, he or she may already be in congestive heart failure or have significant heart enlargement.

Detecting these early signs can be more difficult in our feline friends. Cats will often show no clinical signs apart from being more withdrawn or having a decrease in appetite. Because these signs can be so difficult to detect, routine examinations are incredibly important. These examinations ensure that we are doing all we can to detect changes before there is irreversible damage. This early detection is the key to management of cardiac disease.

There are many cardiac medications available for us to use in dogs and cats. These medications can help decrease cardiac stress, decrease fluid buildup in the lungs, improve overall function of the cardiac muscle, control the rhythm of the heart and help maintain a healthy blood pressure. These medications can slow the progression of heart disease and help treat clinical signs so that you can have as much time as possible with your furry friend.

If you have any questions regarding the cardiovascular health of your pet, contact your veterinarian.

Nicholle R. Hommel is a veterinarian and medical-care coordinator at Society Hill Veterinary Hospital. For more information, call 215-627-5955 or visit

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