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Heart disease is a serious health condition for cats that severely affects the heart's ability to circulate blood. Left untreated, it can lead to congestive heart failure. In this post, our Halifax veterinarians share the types, symptoms, and treatment options for this disease.

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Cats & Heart Disease

Cardiomyopathy (the most common form of heart disease in cats) affects the heart's ability to contract, the strength of those contractions, and how much blood is distributed to the body. A cat's heart contains four chambers. The left atrium and the right atrium are the upper chambers, while the left ventricle and the right ventricle are the lower chambers. In a healthy cat, red blood cells carry oxygen from the cat's lungs to the left side of the heart. The blood then reaches tissues and cells throughout the body. 

Cats with heart disease have poor blood circulation. While valvular heart disease can cause the blood to flow in the wrong direction, heart disease of the muscles can prevent the muscles from contracting as needed to pump blood to where it needs to go. 

Types of Heart Disease in Cats

Heart disease in cats may be either congenital or acquired: 

  • Congenital heart disease is present from a cat's birth and can be inherited. 
  • Acquired heart disease (often referred to as adult-onset heart disease or adult-onset hypertrophic cardiomyopathy), is the most common type of heart disease in cats, and often develops in middle-aged or older felines as a result of wear and tear on the heart. It can also be caused by injury or infection.

In some cases, adult-onset heart disease may develop as a secondary problem, with the primary issue occurring in another area of the body, such as the thyroid gland.

Symptoms of Heart Disease in Cats

In its early stages, heart disease can be difficult to diagnose in cats since most do not exhibit any clinical symptoms until the disease has advanced. 

While not every cat with heart disease will develop all of these symptoms, many cats will display more than one. Symptoms of heart disease in cats include:

  • Poor appetite
  • Difficulty breathing or shortness of breath 
  • Lethargy or inactivity 
  • Elevated heart rate 
  • Difficulty exercising, or not exercising at all 
  • Weight loss 

If you have noticed any of the symptoms listed above in your pet, ask your Halifax or Dartmouth veterinarian for a referral to our veterinary cardiologist at Coastal Care Veterinary Emergency & Referral Hospital. We can perform a comprehensive cardiac exam, conduct diagnostic tests, and develop an individualized treatment plan.

Severe Symptoms of Heart Disease

If your cat is displaying more severe symptoms of heart disease, you may notice the following at home: 

  • Congestive Heart Failure - If your cat breathing fast or with great difficulty, this may be caused by the heart's inability to effectively pump blood, which leads to blood backing up and fluid accumulating in the lungs. 
  • Aortic Thromboembolism - If a blood clot blocks the main artery to a leg, this can prevent blood from reaching the limb. While this often occurs in rear legs, it may happen to any of a cat's four legs and can cause severe pain, weakness, and paralysis. The affected limb may also be cool to the touch and your cat's paw pads may also appear to be pale, purple, or bluish in colour. 

Both of these circumstances are medical emergencies and require attention from a veterinarian as soon as possible. 

How a Veterinarian Diagnoses Heart Disease

When monitoring your cat's heart health, keep in mind that veterinarians and veterinary cardiologists can often diagnose heart disease before symptoms occur. Taking your cat to your family vet for an annual physical examination and blood tests is highly effective at screening your pet for other diseases that can affect the heart.

While blood should typically flow in a smooth path through the heart, heart disease can cause abnormal blood flow, resulting in turbulence or blood being directed incorrectly through a valve (leaky valve), both of which can lead to a heart murmur. 

If your cat is displaying some of the severe symptoms listed above, your veterinarian can listen to your cat's heart with a stethoscope during a physical exam to identify whether a heart murmur (an abnormal sound created during a heartbeat) or an arrhythmia (an irregular heartbeat) are present, which can indicate heart disease. 

Your family veterinarian can also refer you and your cat to Dr. Jeremy Orr, our board-certified veterinary cardiologist who can diagnose and manage heart disease in pets. Dr. Orr can perform a comprehensive cardiac examination and diagnostic testing to identify underlying issues. 

To determine the specific type of cardiovascular disease your pet has and develop a treatment plan, we'll review your pet's medical history and may perform several non-invasive diagnostic tests, including: 

  • Echocardiography (ultrasound of the heart that can help us obtain a definitive diagnosis)
  • Electrocardiogram (ECG/EKG, which evaluates the heart's rhythm)
  • Ambulatory ECG (Holter monitoring, which is often indicated in pets with arrhythmias and a history of fainting)
  • Thoracic radiographs (which help identify congestive heart failure and other pulmonary abnormalities)
  • Blood pressure measurement 

How Long Cats Live After a Heart Disease Diagnosis 

Structural disease typically causes recurring symptoms of congestive heart failure over time and requires lifelong medication. Generally, a cat is likely to survive between 6 and 12 months on average after being diagnosed with congestive heart failure. Your feline friend will also need frequent follow-up visits and additional tests may be required to monitor your cat's heart health. 

Potential Complications of Heart Disease & How They Are Treated 

Unfortunately, there is no cure for heart disease in cats, and damage to the heart's structure is irreversible. It can be challenging to predict whether a cat will develop complications from heart disease. While some cats with moderate heart disease can live a stable, normal life, others develop complications as a result of mild or severe symptoms. Here are some potential complications and treatment options for feline heart disease: 

Blood Clots 

Blood flows much slower in a diseased heart, resulting in blood clots (also referred to as thrombus). These clots can become lodged in essential arteries that extend to the lungs, legs, kidneys, or intestines, or in the heart itself. 

A clot can also become lodged at the end of the aorta (the main blood vessel extending from the heart), which will cause the blood flowing to the rear legs to be blocked). This can lead to paralysis, a severely painful condition and veterinary emergency that requires immediate attention. 

While blood clots are difficult to treat, some cats can recover. However, other clots are then likely to develop. While cats with more severe heart disease are more vulnerable to developing clots, all forms of cardiovascular disease can cause these. An echocardiogram can help to determine whether your cat's heart disease is serious enough to lead to clots. 

Congestive Heart Failure 

When the heart is not able to pump blood effectively throughout the body, the veins may become excessively full and cause this life-threatening condition. Fluid will leak from the veins into other areas of the body. In cats, this excess fluid is often discovered in the lungs (pulmonary edema) or chest cavity (pleural effusion). 

A veterinary cardiologist can perform a thoracic radiograph to diagnose congestive heart failure and prescribe medications to reduce the amount of fluid in the body. Fluid is sometimes drawn from the chest with a needle and syringe. If your primary vet suspects your cat may have congestive heart failure, book an appointment with a veterinary cardiologist as soon as possible. 


A pediatric blood pressure cuff and Doppler monitor can be used to measure blood pressure in cats. Hypertension (high blood pressure) in cats may lead to neurological damage, blindness, kidney damage, and/or worsening heart disease if left untreated. Hypertension is most often seen with hypertrophic cardiomyopathy (HCM). 

Other Treatment Options for Heart Disease

In some cases where heart disease is secondary to a treatable condition such as hyperthyroidism, heart disease symptoms can be managed once the primary condition has been treated. Your cat's cardiologist may prescribe different types of medication in conjunction with other treatments to help reduce the risk of congestive heart failure. These medications can help to relax the heart muscle, slow down the heart rate, and decrease the workload of the heart. Diuretics may be prescribed to reduce fluid overload. 

A low-sodium diet, taurine supplements, oxygen therapy, or surgery are other potential treatment options that can help to remove any accumulation of excess fluid from the chest cavity or abdomen. 

Veterinary Cardiology at Coastal Care Veterinary Emergency & Referral Hospital 

While your family veterinarian can diagnose and treat many health issues, heart disease and other conditions require specialized care and diagnostics to ensure the best possible outcome for your four-legged friend. 

At Coastal Care Veterinary Emergency & Referral Hospital, we believe heart disease is treatable, and our goal is to make cardiac care accessible for pets across Halifax and Dartmouth to improve the quality and length of life of your pet. We are trained to diagnose and treat cardiovascular disease in pets and offer both medical and surgical treatment for cats and dogs with this disease. 

Dr. Orr is board-certified in veterinary cardiology and looks forward to working closely with your pet's primary care veterinarian to create an individual diagnostic treatment plan for your pet. She can also explain your pet's underlying disease and prognosis in easy-to-understand terms. 

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 displaying symptoms of heart disease? Ask your primary veterinarian for a referral to our veterinary cardiologist at Coastal Care Veterinary Emergency & Referral Hospital. We offer diagnostic testing and treatment options for heart problems in pets from Halifax, Dartmouth, and surrounding areas.

Signs of Heart Disease in Cats

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