What is heart disease and congestive heart failure?
Congestive heart failure occurs as a result of progressive heart disease. Heart disease is when the heart starts to fail in its ability to pump blood properly, but in the early stages the body is still able to compensate and the blood and tissues still receives the oxygen they need. When the heart is unable to pump blood properly though your pet’s body and there is not enough oxygen getting around it causes an increase in pressure and fluid that eventually leaks out of the heart to the lungs, around the lungs or into the abdomen. This causes congestion of the lungs and the heart will begin to fail.
Symptoms of heart disease and heart failure
With any progressive disease, symptoms usually start out mild or even unnoticeable, progressing until symptoms are very obvious. The initial stages of heart disease may include:
- increased lethargy, sleeping more
- exercise intolerance
- changes in breathing patterns, breathing more rapidly
These symptoms will worsen as the heart disease worsens, leading to
- difficulty breathing
- loss of appetite
- sudden death
Heart disease is diagnosed by the symptoms your pet is showing and the veterinarian’s physical exam findings. When the veterinarian listens to your pet’s heart and lungs with the stethoscope, the lungs will sound muffled and congested. Diagnostic testing to confirm heart disease and see how far the disease has progressed will also be recommended. If the heart disease seems to be severe or complicated a referral to a veterinary cardiologist specialist will be recommended.
3 view Chest radiographs (x-rays): for heart conditions are recommend. We will take an x-ray of your pet with their right side down, left side down and either on their back or stomach (if they are having any type of respiratory distress the x ray will be taken on their stomach). These 3 views will allow the veterinarian to fully assess the heart, lungs and some blood vessels.
An electrocardiogram (ECG): is a recording of the electrical impulses that are generated when the heart is beating. This may be recommended if the veterinarian hears an abnormal heart beat on examination. An ECG detects disturbances in the heartbeat or heart rhythm.
An echocardiogram: is an ultrasound of your pet’s heart and thoracic cavity. Ultrasounding the heart allows the veterinarian to see the heart beating and pumping blood, view the structures of the heart and detect any other abnormalities with the heart. This procedure gives your veterinarian very useful information in regards to your pet’s heart disease.
Blood pressure: testing is important when dealing with heart disease. Elevated blood pressure puts more strain on the heart, therefore in pets with heart disease, maintaining normal blood pressure is very important. Blood pressure readings are the most accurate if your pet is not stressed, so in-clinic readings can sometimes be unreliable if your pet gets stressed coming to the clinic. To get better readings, we will let you sit in our lounge for a while so your pet can calm down, or (since our blood pressure monitor is portable) we can take the readings out in your car. It takes 10-15 minutes to get 5-7 readings, which we average for the veterinarians to review.
Laboratory diagnostics: such as blood and urine testing may also be recommended to see if there are any other health concerns with your pet. Kidney disease, liver disease, hyper/hypothyroidism, diabetes, pancreatitis, anemia, infection, etc are all health concerns that can be screened for with a blood and urine test.
Treatment and monitoring
The treatment of your pets heart disease will vary on what the underlying cause of the heart disease or how far it has progressed. The goal of treatment for heart disease and failure is to reduce build up fluid around the heart and lungs and to increase blood flow in the body without putting excess stress on the heart. This is to keep your pet comfortable and maintain quality of life.
These are the most common medications used to stabilize heart disease and slow the progression to heart failure. If your pet has heart disease they may be prescribed a combination of theses medications to manage their heart disease.
Angiotensin-converting enzyme inhibitor (ACE inhibitors) benazepril/Fortekor®: This drug slows the conversion of angiotensin I to angiotensin II. Angiotensin II is responsible for causing muscles surrounding blood vessels to contract, thus increasing blood pressure. By lowering the amount of angiotensin II in the body, blood pressure is reduced. This makes it easier for the heart to pump and therefore improving function of a diseased or failing heart.
Diuretics furosemide/Lasix®: This drug is used to treat fluid build up in the body by promoting the kidneys to get rid of excess salt and water in the body. This drug is very effective in treating congestive heart failure, as it pulls fluid off the lungs and excretes it through the urine. When the fluid is gone from around the heart and lungs it allows the heart to pump easier and more effectively.
Positive inotropes pimobendan/ Vetmedin®: This drug increases the strength of the contractions of the heart muscle, making the heart pump more blood forward to the lungs and the rest of the body. It also works as a vasodilolator, lowering the blood pressure in the blood vessels. The dual function of this drug reduces blood pressure and increases the functionality of the heart.
Calcium channel blockers amlodipine/Norvasc®: This drug blocks calcium from entering certain tissues and arteries. Without the calcium, the tissues and blood vessels relax and blood can flow more easily. This in turn will help lower blood pressure.
Changing your pet to a cardiac or aging diet can be beneficial if they have heart disease. These diets are formulated to help manage pets with heart disease/failure and are also good if your pet has any other health concerns associated with aging (kidney disease, chronic pancreatitis etc). These diets are available commercially as prescription diets. Depending on the specific diet, they will contain a mix of the following benefits:
- They contain arginine, L-carnitine, and taurine to promote a healthy heart and maintain heart muscle function.
- Moderate sodium levels help to reduce the work load on the cardiovascular system. This can help control the clinical signs associated with hypertension or sodium and fluid retention.
- Supplemental omega-3 fatty acids (EPA and DHA) are proven to reduce inflammation of the body, helping your pet feel better overall.
- Antioxidants defend cells from free radial oxidation, promoting a healthy immune system.
- They have added vitamin-B complex and magnesium, as these nutrients can be lost through the urine in pets on diuretics.
- Reduced fat to manage pets that may be overweight or have exercise restrictions.
For many pets with congestive heart failure, exercise restriction is an important part of their treatment. Pushing them to go for walks or play can put unneeded stress on their cardiovascular system, worsening the heart disease.
If you’re concerned about heart disease and your pet, please give us a call to set up an appointment!