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Heart Disease in Dogs & Cats: Signs & Symptoms

Just like humans, it is quite common for dogs and cats to suffer from heart disease. In this post, the vets at Broad Street Veterinary Hospital share some of the common causes, symptoms, and treatment options for dogs and cats with heart disease.

Heart Disease in Dogs

The heart is an incredibly important organ and any disease that affects the heart is likely to have negative effects on other organs as well. Unfortunately, it is often difficult to detect heart disease until it has reached a later, more severe stage, but there are some symptoms dog owners should be aware of. It is also important to note that some breeds are more prone to heart disease than others. You should always research breed-specific problems before purchasing a dog to be sure you are prepared to handle any potential complications with your pup's health.

Types of Heart Disease

There are several different types of heart disease that affect dogs. Here are some of the most common:

Valvular Disease - Valvular disease affects the valves of the heart. The valves are little flaps of tissue that act as doors between the chambers of the heart and prevent blood from flowing backward. When a dog is suffering from valvular disease, the valves don't function as they should and cause problems with blood flow through the body. Degenerative valvular disease is common in older small breed dogs such as Chihuahuas and King Charles Cavelier Spaniels.

Arrhythmogenic Right Ventricular Cardiomyopathy - This disease is also referred to as Boxer cardiomyopathy because it happens almost exclusively in boxers. This disease the heart to beat abnormally fast due to a change in the muscle in the right ventricle of the heart. This irregular heartbeat makes the heart unable to properly pump blood through the body.

Heartworm Disease - Heartworms are spread through mosquitos. Once inside your dog, heartworm larvae grow and develop into worms that live and reproduce in the heart and lungs, causing severe discomfort and eventually organ failure in your dog. Heartworm disease is preventable through widely available heartworm preventive medication.

Dilated Cardiomyopathy (DCM) - In dogs with DCM, the heart loses its ability to effectively pump blood through the body. This is a very common disease and may go undetected for quite some time. DCM is common in older large breed dogs such as Great Danes, Irish Wolfhounds, and Dobermans.

Myocarditis - Myocarditis is a cardiac disease in dogs caused by the swelling of the heart muscle. Often, there are no symptoms with myocarditis until it gets severe enough to cause heart failure.

Congenital Abnormalities - Congenital abnormalities are defects in the heart that a dog is born with. There are many different types of congenital abnormalities.

Heart Failure in Dogs

Heart failure is not a disease itself but rather the effect of a heart disease that has gone untreated, or that is not able to be treated. Heart failure occurs when blood is no longer able to be adequately pumped throughout the body by the heart.

Symptoms of Heart Disease in Dogs

Heart disease can be difficult to detect until it has reached a later stage. One key way to catch heart disease early is to bring your pet for regular routine exams By doing so, your vet may be able to catch early signs of heart disease that even the most diligent pet owner may miss. Some common symptoms of heart disease are:

  • Coughing
  • Shortness of breath
  • Fatigue
  • Collapse
  • Distended or bloated abdomen
  • Pale or blue gums

Treatment of Heart Disease in Dogs

Treating heart disease in dogs depends on the underlying cause of the disease. Heart disease can be caused by a number of things including birth defects, heartworm infection, other bacteria or viral infections, toxins, mineral deficiencies, and tumors. Once heart disease is diagnosed, a treatment plan specific to the type of heart disease your dog has will be discussed.

Many types of heart disease require life-long monitoring with frequent diagnostic testing and medications. Some heart diseases, such as congenital defects, can be corrected by surgery.

Preventing Heart Disease in Dogs

Heart disease can be difficult to prevent. Sometimes you can do everything right and your dog could still be diagnosed with heart disease.

Some things you can control are:

  • Buying from a reputable breeder who is testing the dogs they are breeding for genetic heart conditions
  • Avoiding breeds prone to heart disease
  • Keeping your dog on preventive heartworm medication
  • Feeding your dog quality dog food—you can discuss with your vet the best diet for your particular dog
  • Avoiding exposure to toxins and contaminated areas

The Types of Heart Disease in Cats

The most common kind of heart disease in cats is adult-onset hypertrophic cardiomyopathy which is generally caused by an enlargement or thickening of the heart.

Heart disease in cats can be either congenital or acquired:

  • Congenital heart disease in cats is present at birth and can be inherited.
  • Often referred to as adult-onset heart disease, acquired heart disease occurs in middle-aged or older cats because of wear and tear on their heart. It can also result in injury or infection.

In some cases, adult-onset heart disease develops as a secondary problem, with the primary problem originating in some other area of the body such as the thyroid gland.

Symptoms of Heart Disease in Cats

Early symptoms of the disease can be difficult to identify in cats. Most cats do not display any clinical signs until the disease is advanced, at which point cats tend to become more withdrawn and lethargic.

Not every cat will develop all the following symptoms and many cats will have more than one.

  • Poor appetite
  • Weight loss
  • Lethargy or inactivity
  • Difficulty with or discontinuing exercise
  • Regularly elevated heart rate
  • Increased respiratory rate and effort
  • Shortness of breath or difficulty breathing
  • Sudden hind leg paralysis
  • Fainting/collapse

How Heart Disease is Treated in Cats

Unfortunately, there isn't a cure for hypertrophic cardiomyopathy in cats. Damage caused to the structure of the heart muscle is irreversible. In some instances, where heart disease is secondary to another treatable condition like hyperthyroidism, the symptoms may be alleviated once the primary condition is addressed.

Your veterinarian can prescribe different types of medication to help reduce the risk of congestive heart failure in cats. These medications can help to relax the heart muscle, slow down the heart rate and decrease the workload of the heart. Diuretics are usually prescribed to reduce fluid overload.

In addition to medications, other kinds of treatment may be recommended by your vet including a low-sodium diet or oxygen therapy, taurine supplements or surgical procedures to remove excess fluid buildup from the chest cavity or abdomen.

Is Heart Disease Painful for Cats

Some cats with heart disease may develop a painful and paralyzing condition called saddle thrombus. This condition is caused when a blood clot develops in the heart and moves out of the aorta and begins blocking blood flow to your cat's hind legs. If your notice a sudden onset of hind leg paralysis in your cat, contact your vet or seek emergency care immediately.

Life Expectancy for Cats With Heart Disease

Cats with structural heart disease will likely develop recurrent signs of congestive heart failure over time and require lifelong medication. In general, the average survival time after a cat has been diagnosed with congestive heart failure is 6 to 12 months.

Cats that have been diagnosed with congestive heart failure will need frequent veterinary follow-up visits and additional tests may be performed in order to monitor your cat's heart health.

How Early Onset Symptoms of Heart Disease in Cats are Detected

The most important thing to know when it comes to monitoring the heart health of your cat is that vets can often identify heart disease before its symptoms arise. Bringing your cat in to your vet every year for a complete physical exam and blood testing is a highly effective screening for your pet's health issues that may lead to heart disease.

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.

Are you concerned about symptoms of heart disease in your cat or dog? Call our Richmond veterinarians as soon as possible to schedule an appointment - early diagnosis is key!

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