February is all about hearts! My topic this month is about pet heart disease.
What kind of heart diseases can cats and dogs get?
Cats commonly get hypertrophic cardiomyopathy. In this condition, the heart muscle is overworked causing it to increase in size. Overall, the heart size remains the same, but the muscle gets thicker.
Those muscles around the larger chamber, or ventricle, get so large and bulky that the chamber gets very small. This small chamber size only allows a small amount of blood to get circulated with each heartbeat.
Subsequently, blood regurgitates into the smaller chamber, or atrium. It swells up like a balloon, and the blood can settle, causing clots. Sometimes these clots escape into the body. This may cause sudden death if it lodges in an important area, like the heart, lungs, or brain.
Occasionally, the clot goes to the legs and causes a very painful paralysis.
Dogs commonly get two kinds of heart disease: dilated cardiomyopathy and valvular disease.
With dilated cardiomyopathy, the heart muscle is weak and cannot pump blood efficiently. The heart enlarges and becomes dilated and it will start to fail.
In valvular disease, the valves that separate the heart chambers get leaky. When the heart beats, these valves are supposed to block blood flow backwards. If the valves are leaky, blood flows backwards and increases the work that the heart must do. In some cases, this leads to heart failure.
What are the symptoms of heart disease?
In most cases, you’ll notice that your dog or cat cannot tolerate activity. Cats sleep much more. Dogs only tolerate short walks. Unfortunately, these can be signs of aging or arthritis as well.
If you notice any of these symptoms, take your pet to your vet for an exam. Some animals with fluid buildup in the lungs will cough. If the heart is failing, you’ll notice your pet struggling to breathe. That’s a sure sign to see your vet or get to an emergency hospital ASAP.
In some heartbreaking cases, the only symptom is sudden death. This is usually the case when a clot forms and lodges in a vessel to the heart, brain, or lungs.
Your vet will listen for abnormal sounds. The most common abnormalities are a murmur or an arrhythmia.
A murmur is the sound the heart makes when the blood is not flowing smoothly. This is usually a sign that the valves are leaky.
An arrhythmia is an abnormal heart rhythm. Normally the heart beats in a steady beat. If the beat is irregular, blood is not flowing efficiently. Your vet will need to run other tests to see what the cause of these abnormal sounds are.
What kind of testing is done?
The most common tests are blood tests and imaging of the heart and lungs. Blood tests reveal how well the whole body is functioning and to rule out hormonal causes.
Chest X-rays will show the overall shape and size of the heart and if there is any fluid buildup in the lungs. A cardiac ultrasound will preview heart wall thickness, chamber sizes, valve motion, and how well the heart contracts to pump blood.
All of these tests combined will inform your vet what kind of disease your pet has and how to best treat it.
What treatment is available?
In most cases, heart disease is progressive and we’re only able to slow down the disease process.
If your pet is in heart failure and cannot breathe easily, your pet will need to stay in the hospital and have supplemental oxygen. Medication is given to help the heart pump blood and remove fluid in the lungs.
Many dogs and cats can live for extended periods of time with a good quality of life, especially when the disease is caught early. It’s not unusual for dogs and cats with heart disease to be affected by completely unrelated causes.
Dr. Stephanie Oba is a contributing writer and animal physician working at a non-profit rescue organization in San Diego. Opinions expressed in this column are not necessarily those of The Rafu Shimpo.