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Congestive Heart Failure – Treatments for Pets with Heart Disease

Congestive heart failure occurs when the heart is unable to pump an adequate amount of blood, causing an increase in pressure and fluid that eventually leaks out into the lungs or elsewhere. It is not a disease itself but rather a condition that occurs as the result of severe heart disease. The accumulation of fluid in a pet's lungs (called pulmonary edema) or around the lungs (pleural effusion) hinders the normal expansion of the lungs and prevents oxygen from properly moving into the blood stream. As a result, the animal will take deep and rapid breaths in order to get enough oxygen. A pet with fluid in their lungs will not be able to exercise as well, they may cough, they will appear weak and sluggish, and will not have a good appetite, in addition to other symptoms.


The specific treatment for congestive heart failure depends on the underlying heart disease and how severe the heart failure is. The primary goals of treating congestive heart failure are to reduce this buildup of fluid and to increase the amount of blood being pumped by the heart to the lungs and the rest of the body. These outcomes are meant to improve the quality and length of a pet's life. A variety of medications, supplements and diets are available to help reach these goals. One of the most common types of medication used is called an angiotensin-converting enzyme inhibitor, or ACE inhibitor. Examples of these are enalapril (Enacard®), lisinopril and benazepril. These have been shown to improve both clinical signs and survival in dogs and cats with congestive heart failure.

Diuretics are another group of drugs that cause fluid in the body to be taken up by the kidneys and excreted as urine. These are very effective in treating congestive heart failure, since they remove the excess fluid that has built up. There are many different types of diuretics including loop diuretics such as furosemide (Lasix®), thiazide diuretics such as hydrochlorothiazide (Microzide®), and potassium-sparing diuretics such as spironolactone (Aldactone®). Your veterinarian will choose the most appropriate diuretic based on each individual animal.

Another group of drugs, called vasodilators, relax (or dilate) blood vessels in the body and decrease the amount of pressure on the heart and allow it to pump blood forward with greater ease. Examples of these drugs are nitroglycerine (Nitrostat®), hydralazine (Apresoline®), and sodium nitroprusside (Nipride®). ACE inhibitors also have vasodilator effects.

Another group of drugs called positive inotropes may also be administered in certain cases to increase the force with which the heart muscle beats (increased vigor of contraction), allowing it to pump more blood forward to the lungs and the rest of the body. Pimobendan (Vetmedin®) is the most commonly used positive inotrope. Others include digoxin, milrinone, and dobutamine.

In addition to medications, there are other therapies to help improve and or help prevent cases of congestive heart failure. Modifying your pet's diet and limiting the amount of salt they eat is a critical component of treating congestive heart failure. More information on the importance of a proper diet for pets with heart disease, including lists dog and cat foods made especially for these animals, can be found in the Diet section. Directions and tips for giving pills to your pet, as well as lists of acceptable and inappropriate treats are also provided in this section. For many pets with congestive heart failure, exercise restriction is a crucial aspect of therapy in order to reduce the risk of worsening their condition or even death.

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