Heart failure is a condition, caused by an abnormality in the structure or the function of the heart, in which it is unable to pump normal quantities of blood to the tissues of the body. The heart is a pump, and when it fails, it often leads to fluid retention in the lung and the body cavities leading to congestive heart failure.
There are many causes of heart failure in cats, including: Birth (congenital) defects of the heart
Degeneration of the heart valves
Heart muscle disease (cardiomyopathy)
Diseases of the pericardium (the lining around the heart)
Irregular electrical rhythms of the heart (arrhythmia)
Cats of any age and any breed can develop heart failure. The most common cause of congestive heart failure in cats is heart muscle disease (cardiomyopathy), though anemia and uncontrolled hyperthyroidism can also lead to this problem.
Heart failure affects your cat by reducing the amount of blood that is pumped to the muscles, leading to fatigue. In addition, most cases of heart failure are associated with accumulation of fluid (edema) in the lungs, the chest cavity (pleural effusion), or the abdominal cavity (ascites). This fluid accumulation can lead to shortness of breath and other problems such as coughing and difficult breathing.
Some of the symptoms of heart failure, and the progression of heart failure, are related to increased activity of the nervous system and to increased concentrations of circulating hormones (and related chemicals).
What to Watch For
Shortness of breath
Difficult breathing (dyspnea)
Your veterinarian may suspect CHF after examining your pet, but he will probably run several diagnostic tests to confirm the diagnosis and underlying cause. Tests may include:
General physical examination with emphasis on stethoscope examination (auscultation) of the heart and lungs
A chest radiograph (X-ray)
Measurement of blood pressure
An electrocardiogram (EKG)
Ultrasound examination of the heart (echocardiogram)
Treatment for congestive heart failure will vary depending on the underlying cause. This may include one or more of the following:
Initial treatment may require hospitalization with a diuretic, oxygen, and other drugs such nitroglycerine paste.
A diuretic ("water-pill") such as the drug furosemide (Lasix®)
Pleural effusion (fluid around the lungs) may require thoracocentesis, which is insertion of a small needle in order to drainsome of the fluid. This often improves breathing and makes your cat more comfortable.
Nitroglycerine, which comes in the form of a paste, is often used topically (spread on the ear or abdomen or other relatively hairless area).
Other diuretics, such as spironolactone.
Angiotensin converting enzyme inhibitor such as enalapril (Enacard) or benazepril. These drugs block some of the harmful hormones that circulate in heart failure and prevent salt retention.
A diet limiting sodium intake and preventing fluid retention.
Use of digoxin (Lanoxin; Cardoxin)
At home, administer all veterinary prescribed medications on a regular basis. Be aware of your cat's general activity, exercise capacity and interest in the family activities. Keep a record of his appetite and ability to breathe comfortably (or not), and note the presence of any symptoms such as coughing or severe tiring.
Do not stop medication or change the dosage without checking with your veterinarian. Most medications are for the life of your cat. And never withhold water, even if your pet urinates more than normal, unless specifically instructed to do so.
Difficult breathing is usually an emergency. See your veterinarian immediately.
In general, heart failure cannot be prevented, although early diagnosis of the underlying cause can provide an improved quality of life. Once diagnosed, you should prevent excessive physical activity or excitement, avoid high heat/humidity and avoid high salt (sodium) foods or treats.