Holter Monitor in Dogs

By Ryan Llera, BSc, DVM; Ernest Ward, DVM

What is a Holter monitor?holter_monitor_in_dogs-1

A Holter monitor is a portable device used to continuously monitor the electrical activity of the heart. Its extended recording period is useful for observing occasional or intermittent cardiac arrhythmias that may be difficult to identify in during a routine clinical examination. Holter monitors are commonly used in Boxer Dogs and Doberman Pinschers to diagnose specific forms of heart disease and abnormal heart rhythms.


What does a Holter monitor do?

The monitor is usually worn for twenty-four hours during normal activity. You should keep a diary of what activities your dog does while wearing the monitor such as taking a walk, eating, sleeping, or playing. There is a button on the monitor for you to press allowing you to mark an observed event such as a fainting episode. After twenty-four hours, you will return the monitor and diary to your veterinarian's office. Your veterinarian will analyze the recorded ECG looking for abnormalities.

Why does my dog need to wear a Holter monitor?

A Holter monitor is typically used for patients with a history of syncope (fainting) or if your veterinarian detected abnormal or irregular heartbeats during a clinical examination of your dog. Some of the uses include:

  • determine heart rate variability during normal activity, exercise, and rest or sleep
  • diagnose the type of arrhythmia (abnormal or irregular heartbeat or rhythm) in order to determine the correct treatment
  • analyze the effectiveness of prescribed cardiac drugs
  • evaluate pacemaker function

How does my dog wear a Holter monitor?

The Holter monitor used for dogs consists of a special vest containing the monitor attached to several ECG lead wires. It is very unobtrusive, and most dogs ignore its presence very quickly. Your dog will most likely have several areas of fur shaved to attach the ECG leads to the skin.

"It is very unobtrusive, and most dogs ignore its presence very quickly."

If your dog requires the use of a Holter monitor, your veterinarian will give you specific instructions on its use. This relatively simple but highly effective device has saved countless human and animal lives since first introduced almost seventy years ago.

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