Congestive Heart Failure in Cats: Signs, Symptoms, & Prognosis

Just like humans, it is common for cats to suffer from congestive heart failure. In this post, the vets at Veterinary Medical and Surgical Group (VMSG) share some of the common causes, symptoms, and treatment options for cats with congestive heart failure.

What is Congestive Heart Failure in Cats?

Congestive heart failure (CHF) is a term that refers to the heart's inability to pump enough blood to the body. Due to this, blood starts to back up into the lungs and fluid accumulates in the chest, abdomen, or both. This lead to further constriction of the heart and lungs, and limits oxygen flow throughout the body. There are many causes of CHF in cats, but the two most common causes are:

• Mitral valve insufficiency (MVI), which refers to a leaky mitral valve, which is the valve between the left atrium and the left ventricle.
• Dilated cardiomyopathy (DCM), which is when the heart chambers enlarge and lose their ability to contract.

Clinical signs of CHF vary depending on whether the cat has left- or right-sided heart failure.

Right-sided congestive heart failure (RS-CHF)

This occurs when a heart contraction causes some blood to leak into the right atrium from the right ventricle rather than being pushed through the lungs and becoming oxygenated. As a result, the main circulation system becomes congested with blood, and fluid accumulates in the abdomen, interfering with adequate organ function. Excess fluid might also build up in the limbs and cause swelling known as peripheral edema.

Left-sided congestive heart failure (LS-CHF)

This occurs when blood from the left ventricle leaks back into the left atrium through the mitral valve rather than getting pumped into the body's systemic circulation when the heart contracts. This causes pressure overload to the left side of the heart. Fluid begins to leak into the tissue of the lungs, causing swelling known as pulmonary edema, which leads to coughing and difficulty breathing.

What Causes Congestive Heart Failure in Cats?

A variety of factors can cause congestive heart failure in cats. It is most commonly caused by a condition in which the walls of the heart thicken (hypertrophic cardiomyopathy), but it can also be caused by thyroid disease, high blood pressure, or birth defects, among other things. Congestive heart failure can occur in cats of any age, breed (though it is most often associated with the Maine Coon), or gender, but it is most common in middle-aged to older cats.

CHF can also develop in a heart that's been weakened by other heart conditions, so it's essential to do what you can to prevent heart disease from occurring in your pet, including preventing obesity and providing heartworm prevention.

Symptoms of Congestive Heart Failure in Cats

The most common symptom of congestive heart failure in cats is difficulty breathing. Other symptoms can include:

• Coughing
• Lethargy
• Weight loss
• Abdominal bloating (due to fluid accumulation)
• Loss of appetite
• Vomiting
• Loss of consciousness

If you notice any of these symptoms, you should have your cat checked by your vet without delay.

How to Diagnose Congestive Heart Failure in Cats

Make sure to describe all of your cat's symptoms to your vet. They will want to know what your cat eats, what medications and supplements they may be taking, and if they are currently on heartworm protection. The vet will listen to your cat's chest and may want to run some diagnostic tests, including:

• Blood and urine test
• Chest X-rays
• EKG 
• Ultrasound 
• Heartworm antigen test
• Holter monitor 

Treating Congestive Heart Failure in Cats

Your cat will likely be placed on several medications. These include a diuretic to remove the excess fluid buildup in the lungs and body, an angiotensin-converting enzyme (ACE) inhibitor which has been shown to improve clinical symptoms and increase survival in cats with CHF, and a vasodilator to relax the body's blood vessels. In some cases, another type of drug known as a positive inotrope might be prescribed to strengthen the force of contractions in the heart and improve blood flow.

If your cat struggles to breathe, your vet may administer oxygen therapy until he's able to breathe adequately on his own. Depending on how much oxygen is needed, this might require hospitalization.

End-Stage Congestive Heart Failure in Cats

The symptoms of end-stage congestive heart failure in cats can include:

• A chronic cough or wheezing
• Lack of appetite and nausea
• An increased heart rate
• Confusion
• Dyspnea – shortness of breath
• Swellings caused by trapped excess fluids
• Inactivity

Unfortunately, this stage of congestive heart failure might be when you have to euthanize your cat. Be sure to speak with your veterinarian about all treatment options first.

Congestive Heart Failure In Cats Life Expectancy

Make sure to bring your cat for regular visits with your vet and stick with your treatment plan. Unchecked heart problems can make things harder on your cat and even shorten their life. With the right treatments, care, and monitoring, your cat can live a long, comfortable life.

Unfortunately, there is no cure for CHF at this time, and treatment is aimed primarily at improving quality of life. Advances in medications used to treat this condition have vastly improved the overall prognosis. Vigilant home care and lifestyle management may help to extend survival from months to years. The sooner this condition can be identified and treatment is started, the better the chances are of extending your cat's life.

Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.

Is your cat showing symptoms of congestive heart failure? Contact Veterinary Medical and Surgical Group (VMSG) for an appointment with our board-certified veterinary cardiologist.

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