Crystal Connor, DVM
As an emergency veterinarian, one of the most common health crises I deal with is congestive heart failure (CHF). Animals, both dogs and cats, of any age may develop this disease, but it is most common in older pets.
Why does CHF occur? This disease is caused by an abnormality of the structure and/or the function of the heart. The heart is responsible for pumping blood to the tissues of the body. When this pump fails, the blood does not get to where it needs to be and instead ‘backs up.’ This results in an accumulation of fluid in or around the lungs and/or within the abdomen. In dogs, we most often see CHF result from an aging or leaky heart valve, whereas in cats, it is more commonly related to structural abnormalities within the heart, such as thickening of the heart muscle.
Clinical symptoms of heart failure can vary, but most commonly, dogs will exhibit coughing, lethargy, breathing difficulties, collapse, and pale or purple/blue gum and tongue color.
Cats do not typically cough with heart disease and often do not exhibit any symptoms until they are in a severe crisis. Owners may notice more vague signs, such as weight loss, lethargy, and poor appetite. When in full blown heart failure, cats will often have labored breathing, which may or may not be accompanied by open mouth breathing (panting). Open mouth breathing is NEVER normal in cats. They can also vocalize and appear very distressed. Sometimes owners are not even aware their pets have heart disease until they are in actual heart failure.
How is this heart condition diagnosed? Your veterinarian will be able to diagnose CHF through physical exam findings combined with changes seen on chest x-rays. The cat or dog generally presents for labored or difficulty breathing. In addition to breathing abnormalities, your veterinarian may detect one or more signs, including a heart murmur, ‘wet’ lung sounds, or a low body temperature.
A blood pressure measurement and a recording of the electrical activity of the heart (EKG) should also be performed as part of a thorough evaluation.
For patients experiencing CHF, emergency treatment is required. Initial treatment varies depending on the underlying cause of the heart failure, but commonly involves hospitalization with oxygen supplementation and diuretic therapy, use of medications designed to increase the loss of water and salt from the body. If fluid is present around the lungs, your pet may require a procedure to drain the fluid from the chest cavity, a procedure routinely performed by emergency veterinarians. This procedure often improves breathing, making the patient much more comfortable.
Blood work is also needed to help evaluate any underlying metabolic changes, especially kidney disease. It is important to know if kidney disease is present as the treatments for this and heart failure are contradictory and greatly effect outcome.
The primary goal with emergency treatment is to get the patient out of heart failure. Once stabilized, additional cardiac evaluation can be sought. This involves a consultation with a veterinary cardiologist, who will perform an ultrasound of the heart (echocardiogram) to evaluate structure and function, as well as how blood is flowing through the heart.
Echocardiograms are the best and often only way of identifying diseases of the heart valves and/or heart muscle, as well as detecting fluid around the heart, cardiac tumors, and birth defects. This “real time” examination of the heart will determine which underlying heart disease has caused the failure. This also helps determine what specific treatment is needed to slow the progression of heart disease and permits a more accurate prognosis for your pet. The cardiologist will also be able to track your pet’s progress through treatment and make adjustments as needed.
Heart failure cannot be prevented, however, early detection and implementation of a custom tailored treatment plan can slow the progression of disease and provide an improved quality of life. I encourage all owners to have their pets examined at least once a year, as these visits can be key to early diagnosis of heart disease (in addition to other health conditions).