Updated on November 29, 2015
Matters of the Heart
Just like us, our dogs and cats can develop heart disease. What may surprise you is that they don’t experience heart attacks (myocardial infarctions), the most common human heart health issue. This is likely because dogs and cats don’t live for multiple decades, the time needed for substantial amounts of plaque to accumulate within the coronary arteries. (They don’t smoke cigarettes either!)
Causes of heart disease in our pets
Dogs and cats can develop a variety of heart diseases. Some occur more commonly in particular sizes and breeds. Others, such as heartworm disease, affect dogs and cats of all shapes, sizes, and breeds.
The most common cardiac problems in dogs and cats include:
- Congenital (birth) defects: This category includes faulty heart valves, wall defects between chambers of the heart, and blood vessels that are abnormally configured. These abnormalities alter normal blood flow in and around the heart.
- Heartworm disease: In the infected dog or cat, long spaghetti-like worms set up housekeeping within the heart and arteries that supply the lungs. Left untreated, heartworms can cause both heart and lung disease.
- Valve disease: Valves control normal blood flow in and out of the four chambers of the heart. Age-related heart valve degeneration occurs commonly, particularly in small breed dogs. The resulting “valvular insufficiency” leads to heart failure in some, but not all cases. A relatively uncommon disease that can disrupt valve function is endocarditis, a bacterial infection that develops on one or more of the heart valves.
- Cardiomyopathy (disease of the heart muscle): The heart muscle can become too thin and flabby (dilated cardiomyopathy) or too thick and stiff (hypertrophic cardiomyopathy). Both conditions impair the normal pumping action of the heart.
- Arrhythmias (alteration of the normal rhythm of heart beats): An abnormal heartbeat here and there causes no problem, but multiple abnormal beats can produce significant symptoms.
Warning signs of heart disease
The heart is a muscular pump responsible for circulating oxygen rich blood throughout the body. When the pump fails, not only can abnormal fluid accumulations occur within the body, the animal develops symptoms caused by decreased oxygen supply.
Early warning signs of heart disease can include:
- Increased respiratory rate
- Restlessness during sleep
- Decreased stamina
- Vomiting (occurs in cats)
More advanced heart disease may cause:
- Loss of appetite
- Labored breathing
- Distention of the abdomen with fluid
- Blue/purple tinged tongue and gums
- Sudden death
- Sudden paralysis of the hind legs caused by a blood clot within the aorta (occurs in cats)
Diagnosis of heart disease
Tests used to confirm the diagnosis of heart disease commonly include:
- A thorough physical examination that includes auscultation (listening to the heart and lungs with a stethoscope)
- Blood tests including screening for heartworm disease
- An electrocardiogram (ECG) to evaluate the rhythm of the heartbeats
- Chest x-rays to evaluate the size of the heart and identify abnormal fluid in or around the lungs
- An echocardiogram (an ultrasound evaluation that provides a look inside the heart) to evaluate valve function, chamber size, and the strength of heart contractions
Treatment of heart disease
While many canine and feline heart diseases are not curable, they are often very treatable. Medications are the mainstay of treatment for most types of heart disease. They are used to mobilize excess fluid accumulating in the chest, lungs, and/or abdomen. Drugs are also used to decrease the workload on the heart, enhance the strength of heart contractions, and prevent blood clots. If a heart rhythm abnormality is detected, an antiarrhythmic drug may be prescribed.
Some types of heart disease are best treated with surgery or a specialized procedure. They may involve installation of a pacemaker, repair of a defective heart valve, or correction of a birth defect.
Prevention can reap wonderful benefits when it comes to heart disease. An example is the use of medication to prevent heartworm disease in dogs and cats. A thorough physical examination performed by a veterinarian once a year (twice yearly for senior dogs and cats) is another excellent preventive measure. These exams provide a golden opportunity for early disease detection. In many cases, the earlier heart disease is detected, the better the long-term outcome.
Questions for your veterinarian
If your four-legged best friend has heart disease, here are some key questions to ask your veterinarian.
- What type of heart disease does my pet have?
- How is it best treated?
- How will I know if treatment is working?
- What symptoms should I be watching for?
- When should my pet be rechecked?
- Can you refer me to a specialist? Whenever a serious disease is suspected or diagnosed, a second opinion is a good idea. Additionally, an echocardiogram and other advanced cardiac procedures require specialized equipment and skills. They are best performed by a veterinarian with extra training in cardiology, internal medicine, or radiology.
Have you ever cared for a dog or cat with heart disease? If so, what type and what was the outcome?
Wishing you and your four-legged family members good health and happiness throughout the holiday season,
Nancy Kay, DVM
Diplomate, American College of Veterinary Internal Medicine
Author of Speaking for Spot: Be the Advocate Your Dog Needs to Live a Happy, Healthy, Longer Life
Author of Your Dog’s Best Health: A Dozen Reasonable Things to Expect From Your Vet
Recipient, Leo K. Bustad Companion Animal Veterinarian of the Year Award
Recipient, American Animal Hospital Association Animal Welfare and Humane Ethics Award
Recipient, Dog Writers Association of America Award for Best Blog
Recipient, Eukanuba Canine Health Award
Recipient, AKC Club Publication Excellence Award
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Please visit http://www.speakingforspot.com to read excerpts from Speaking for Spot and Your Dog’s Best Health. There you will also find “Advocacy Aids”- helpful health forms you can download and use for your own dog, and a collection of published articles on advocating for your pet’s health. Speaking for Spot and Your Dog’s Best Health are available at www.speakingforspot.com, Amazon.com, local bookstores, and your favorite online book seller.