Congestive Heart Failure in Cats

Congestive heart failure in cats is a life-threatening condition that requires immediate medical treatment. Early detection may significantly increase the chance of survival. If a cat is displaying possible symptoms, a prompt veterinary consultation is warranted.

Congestive heart failure (CHF) is a condition that occurs when insufficient blood is circulated throughout the body, causing fluid to back up into the lungs. Failure can occur in either the right or left side of the heart, or in both sides. It is commonly caused by a thickening of the heart walls, also known as hypertrophic cardiomyopathy.

Symptoms may develop slowly, making them easy to miss unless owners are vigilant. Affected cats may display one or more of the following symptoms:

• Difficulty breathing
• Rapid breathing
• Weakness/lethargy
• Increased heart rate
• Decreased appetite
• Hind limb paralysis
• Unusual lung sounds
• Pale or blue-tinted mucous membranes
• Heart murmur
• Enlarged liver
• Abdominal distension 
• Collapse
• Sudden death

Congestive heart failure can affect cats of any age, breed, or gender. It occurs more often in cats that are middle-aged or older. There is also evidence that the Maine Coon breed may have a genetic predisposition. Common causes of CHF include:

• Hypertrophic cardiomyopathy 
• Thyroid disorder
• High blood pressure
• Pericardial effusion (fluid surrounding the heart)
• Anemia
• Abnormal heart rhythm
• Heart defects
• Narrowing of aortic artery
• Heartworm disease
• Tumors
• Pregnancy
• Birth defects 

The treating veterinarian will review the cat's full medical history. Owners should be prepared to discuss details regarding the onset and severity of symptoms and share any theories regarding any other possible causes. Since the condition is sometimes hereditary, any information that can be provided regarding the cat’s family line will also be helpful. 

A physical exam will be performed and standard lab tests will be ordered. These include a complete blood count (CBC), thyroid test, electrolyte panel, biochemical panel, urinalysis and heartworm test. Cats may also be tested for feline immunodeficiency virus (FIV) and feline leukemia (FeLV). Using a stethoscope, the vet will be able to note sounds of congestion which would indicate the presence of fluid in the lungs. Blood pressure will be measured and visual diagnosis may be made using chest X-rays, electrocardiogram (ECG) and/or echocardiogram.

Congestive heart failure caused by hyperthyroidism may be reversed once the thyroid condition has been successfully treated. In other cases, the treatment plan will be based on the severity of symptoms and the underlying cause of the condition:

Hospitalization

If symptoms are severe, particularly if the cat is having difficulty breathing or has extremely low blood pressure, hospitalization may be required. Oxygen therapy may be administered when there is fluid surrounding the heart or lungs, and the fluid may need to be drained. This will help to ease pressure on the heart, makes breathing easier. When fluid build-up has been removed, the heart is able to pump blood more efficiently. If fluid is present in the chest or abdomen, it may be removed using a technique called tapping.

Surgical Treatment

Surgery may be recommended to treat cases of congestive heart failure that are caused by a birth defect or a congenital or acquired heart valve disease. This treatment option is often expensive and requires a surgical specialist. 

Symptom Management

In most cases, congestive heart failure it is not curable. Prescription medications can be used to control symptoms and improve the overall quality of life. Diuretics help to reduce fluid build-up, and vasodilators or ACE inhibitors ease the flow of blood through the body by dilating the blood vessels. Positive inotropes cause the heart to beat more forcefully, which increases the amount of blood that is pumped through the body. Prescription medications will likely need to be used for the remainder of the cat’s life.

Cats that have been diagnosed with congestive heart failure will need frequent follow-up visits. During the appointments, it is likely that blood tests, radiographs, and echocardiograms will be performed in order to monitor the cat's heart health. It is important to attend all follow-up appointments as medication may need to be adjusted periodically.

A low-sodium diet that is balanced and highly nutritious will likely be recommended. There are many commercially-available cat foods that meet this requirement. Diet is very important to successful recovery, and no changes should be made without first checking with the veterinarian. 

In some cases, the vet will recommend a moderate exercise plan intended to strengthen the heart while keeping blood pressure at a controlled rate. If the vet has not specifically recommended exercise then the cat should be kept calm and activity should be limited. When cats are unwilling to comply, owners may need to take preventative measures. Periodic cage rest may be necessary and it may be helpful to set up barriers to limit space available for running and jumping.