How to fit a dog with a Holter monitor


1. Cut or tear 10 pieces of white tape approximately 2 inches (5 cm) long

Strips of tape, cut and ready to apply.

2. Shave 5 spots about 2 inches x 1.5 inches (5 cm x 4 cm) to form a circle around your dog\u2019s chest

Start by shaving a spot directly in between the shoulder blades. Next, on your dog’s right side, shave a second spot halfway between the spine and the sternum, and a third spot on the chest behind the elbow. Do the same on the left side of the chest for spots 4 and 5.

Each spot should be 1 to 2 inches (2.5 to 5 cm) away from each other with the last spot being directly caudal (toward the tail) to the elbow of the dog. Make sure that each spot is well shaved by shaving against the fur. Try to keep the spots symmetrical on either side of the dog.

Shaved patches on dog.

3. Attach cables to the patches

Remove the backing, add the electrode gel and stick the white electrode patch to the shaved area between the shoulder blades. Take two pieces of the prepared white tape and place over the sides of the electrode. Do not cover the colored part, just the back of the sticky electrode.

Attaching to the dog

4. Attach patches to the dog

Remove the backing, add the electrode gel and stick the white electrode patch to the shaved area between the shoulder blades. Take two pieces of the prepared white tape and place over the sides of the electrode. Do not cover the colored part, just the back of the sticky electrode.

Electrode attached to dog and tape being applied to best secure it.

5. Red electrode

Proceed to the next shaved patch down the left side of the dog. Attach the red colored electrode to this spot and place two pieces of white tape to either side of the electrode.

Close up image of electrode on dog with 2 pieces of tape securing it.

6. Brown electrode

Continue down the left side of the dog. Place the brown electrode in the same manner as the red electrode.

7. Green electrode

Go to the right side of the dog. Place the green patch on the middle-shaved area and the black patch on the lowest area, behind the elbow.

Note: It is very important for the electrode patches to have excellent contact with the dog’s skin to avoid artifacts, which interferes with the recording of the Holter monitor.

Dog with all electrodes attached.

8. Secure with Elastikon

The lead wires and cable should then lay forward on the dog, so they are sticking out toward the neck while the Elastikon is taped on. Place a strip of Elastikon over all the electrodes and the white tape. Start on the right side of the dog and attach it approximately an inch below the black electrode. Hold the end against the dog’s body while unrolling the Elastikon and continue to stick it to the dog while unrolling it over the dog’s back. Wrap the Elastikon all the way around the dog by going under the dog’s chest. Once the Elastikon has been placed, firmly press down on it over the areas with the electrode to help keep the patches and electrodes in place.

Note: Do not pull too tightly. Elastikon stretches and you could make it too tight around the dog. Lay the tape loosely onto the dog, do not pull or tug it.

Dog with wrap around chest and over all electrodes to secure them.

9. Apply the Holter vest

The Holter vest has a pocket on the top for the monitor and a hole on the underside to feed the patient cable through. Insert the end of the patient cable through the hole and up through the pocket.

A note about our vests: They are always machine-washed between patients, but the fur does not always come off the fleece and Velcro.

Interior of vest worn by dog while Holter monitor is attached.
Exterior of vest worn by dog while Holter monitor is attached.

Adjust the Velcro straps under the neck and belly to ensure a snug but comfortable fit.

Vest being put on dog.

Attaching the monitor

10. Prepare the monitor

With the monitor face down, the cable connection port toward you and the words Trillium 5000 at the top, the left side of the monitor is where the memory card has been inserted for you. You will not need to access this compartment.

The right-side door is for the battery. Open the battery compartment and insert a AA battery, observing the polarity diagram in the compartment. Securely close the battery compartment.

Attach the cable to the monitor. With the monitor facing up and the Forest Medical logo toward the right, attach the head of the patient cable to the cable port. The cable leads should go to the right. Pinch the long sides of the cable head and snap it into place on the monitor.

Close up image showing battery compartment for monitor.
Close up image of Holter monitor as it is being set up to record data.

11. Start the monitor and adjust the settings

Turn on the monitor by pushing any keypad button. The first screen will ask you to input a patient ID number. Ignore this screen and scroll to the right using the → button. You should be able to see the ECG tracing on CH1. Push the → button repeatedly to scroll through CH2, CH3 and the SETTINGS menu until you get to the DATE/TIME menu.

If the date and time are correct, press the ⤶ button. Or use the up and down arrow buttons to move to the item that needs to be corrected. Use the left and right arrow key to change the time or date. Press the ⤶ button again to accept the changes.

Start the Holter recording by using the right arrow key to move over to the START menu, then press the ⤶ key to start the recording.

Close up of screen on monitor.
Close up of monitor.

12. Secure monitor to vest

Place the monitor into its protective pouch and then put it into the pocket on the back of the vest. Coil the rest of the patient cable and push it into the pocket as well to protect it from chewing and scratching.

Note: Because patient cables are expensive to replace, if your dog damages the cable, you will be billed for a replacement.

Monitor being slipped in the pouch on the vest.

13. Record keeping

Record the start time on the patient diary. It is important to make a note of your dog’s activity level on the diary, even if significant episodes are not observed.

Important: The monitor needs to remain running for 24 hours, at which time it will shut itself off and the screen will be blank. While the monitor is recording, we encourage you to let your dog participate in normal daily activity—the only thing to avoid is getting the monitor wet (baths, swimming, snow/rain).

Removing the Monitor

  1. Leave the monitor in the vest pocket with the patient cable attached to the port.
  2. Remove the vest and carefully remove the Elastikon. DO NOT use scissors.
  3. It is best to remove the Elastikon from the front to the back, instead of up and around, so that it peels off with the grain of the fur. This can be somewhat painful, so use adhesive remover for sensitive dogs.
  4. Discard the battery, Elastikon, white tape, and electrode patches.
  5. Please return any unused supplies.