Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)

What is Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) ?

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic heart abnormality typically detected in middle-aged-to-older Boxer dogs. In dogs with ARVC, the right pumping chamber—called the ventricle—muscle of the heart is replaced by fat and sometimes fibrous tissue. This can cause abnormal heart rhythms which, when severe, can result in lethargy or collapse associated with excitement or exercise. In very severe cases, sudden death can occur.

Some dogs with ARVC can also develop Dilated Cardiomyopathy (DCM), a more severe form of ARVC. DCM is a condition whereby the heart muscle becomes weak and dilated. In severe cases, this can result in congestive heart failure.

Diagnose & Monitor

Thankfully, most dogs with ARVC feel completely normal as long as their arrythmias are well controlled. We will work closely with you and your family vet to ensure that your dog gets the best care possible.

ELECTROCARDIOGRAM (ECG) & HOLTER MONITORING

The best way to test and screen for ARVC is with a Holter monitor. At the hospital, your dog is fitted with a vest that contains an ECG monitor. Your pet then wears the monitor at home for 24 hours. If a significant arrhythmia is detected, medications may be started based on its severity and type. Holter monitoring is then typically repeated after medications are initiated to monitor response to therapy.

ECHOCARDIOGRAM (HEART ULTRASOUND)

Since some dogs with ARVC can develop Dilated Cardiomyopathy, an echocardiogram may also be recommended, especially if your pet has a heart murmur. This heart ultrasound is the best way to evaluate heart structure and function. Because some antiarrhythmic medications can affect heart function, it is also important to perform an echocardiogram prior to starting these medications.

Did You Know?

Genetic Testing

ARVC is inherited through a genetic mutation. There is a test for the striatin mutation; however, dogs that test positive for the mutation will not necessarily develop significant ARVC. Dogs with two copies of the mutation are more likely to develop significant heart disease. Genetic testing is not typically recommended for household pets but can be a useful screening tool for breeders.

Follow Up & At-Home Care

Once your dog’s cardiologist determines that the disease is well controlled, repeat Holter monitoring is typically recommended at least twice a year. An echocardiogram may also be recommended periodically.

It is important to remember that your pet is at greatest risk of having an episode during extreme exercise. In dogs with severe ARVC, highly strenuous activities should be limited. Contact us immediately if your pet develops collapse or fainting episodes with exercise, as these episodes can signal worsening arrhythmias.

Frequently Asked Questions

What causes Arrhythmogenic Right Ventricular Cardiomyopathy?

ARVC is primarily caused by a genetic (inherited) defect.

In affected animals—especially Boxers—mutations in proteins that help heart muscle cells stick together (desmosomes) lead to gradual damage. Over time, normal heart muscle is replaced with fatty or fibrous tissue, particularly in the right ventricle. This disrupts the heart’s electrical system and causes abnormal rhythms.

What are the signs to watch for?

♦Fainting (Syncope)
♦Weakness or collapse
♦Irregular heartbeat
♦Exercise intolerance
♦Sudden death in severe cases

How is it diagnosed?

Diagnosis may include:

ECG (electrocardiogram)
Holter monitor (24-hour heart rhythm recording)
Echocardiogram (heart ultrasound)
Genetic testing (in some cases)

What is a Holter monitor and why is it important?

A Holter monitor records your pet’s heart rhythm over 24 hours, helping detect abnormal rhythms that may not show up during a short exam.

How Do I Schedule?

Please call us at 720-510-7707 to book a consultation.