Freestyle Libre for dogs: Uses, dosage, and safety

In this article:

• What is Freestyle Libre used for in dogs?
• Safety
• Alternatives

In this article

• What is Freestyle Libre used for in dogs?
• Safety
• Alternatives

FreeStyle Libre is a prescription continuous glucose monitor. It consists of a sensor worn on the skin that monitors tissue glucose levels and a smartphone app or dedicated reader that scans and stores blood glucose level readings. While FreeStyle Libre is used long-term in people, veterinarians use it for a few days to two weeks to manage insulin treatment in dogs. FreeStyle Libre is not FDA approved for veterinary use. The manufacturer will not provide any support or help when the device is used on animals.

RELATED: Save up to 80% on Freestyle Libre

What is Freestyle Libre used for in dogs?

FreeStyle Libre is a medical device that continually monitors glucose levels in diabetic patients who are taking insulin. Sensors are placed on the skin and can send readings to a device or app. 

People on insulin also have the option of using a continuous glucose monitor to get real-time measurements of glucose concentrations. Almost all require a prescription. FreeStyle Libre is one option. A sensor the size of a large coin is affixed to the skin. A small needle on the underside of the sensor penetrates the skin. The sensor continuously reads tissue glucose levels. Readings are taken by placing a monitoring device or smartphone on or near the sensor. 

In people, these devices can be used for months or years. Long-term use on a dog is not practical. Many dogs dislodge the sensors or get them off in a few days; as many as 60% to 80% of dogs manage to get the sensor loose. Though not practical for long-term use, veterinarians can use FreeStyle Libre as an alternative to lengthy or expensive hospital stays when assessing insulin treatment.

Diabetes

Diabetes is a common disease in dogs, affecting about 1% of dogs. While most people have Type 2 diabetes, most dogs are diagnosed with Type 1 diabetes. Canine Type 2 diabetes is rare. No matter what type of diabetes a dog has, the standard treatment is insulin.

Insulin treatment often requires a lengthy assessment process called blood glucose curves. A BGC is typically a 12-hour in-hospital procedure in which the dog’s blood glucose levels are tested every two hours. These tests allow veterinarians to fine-tune insulin dosages to prevent blood sugar problems. 

If possible, veterinarians will typically perform their first BGC shortly after insulin therapy starts. After that, the America Animal Hospital Association recommends blood glucose curves:

• Every three months 
• When the type of insulin is changed
• When a dog on insulin shows symptoms of diabetes, high blood sugar (hyperglycemia), or low blood sugar (hypoglycemia)

Some veterinarians recommend using a continuous glucose monitoring system like FreeStyle Libre instead of blood glucose curves. The dog can go home with an attached sensor rather than stay at a clinic or hospital for several hours. The veterinarian also gets far more data from the system because FreeStyle Libre can provide minute-by-minute glucose readings or the pet’s glucose levels for up to two weeks. 

There are other reasons a veterinarian may prefer using FreeStyle Libre rather than blood glucose curves:

• FreeStyle Libre can provide data about the dog’s glucose concentrations for up to two weeks. During that time, the vet can change the insulin dose and monitor the effects in real time.
• Even if the dog dislodges or removes the sensor in a few days, the sensor provides more glucose readings than a standard blood glucose curve. 
• The veterinarian can regularly access glucose data on the internet. They can make real-time adjustments to the insulin dose based on the information they’re getting.
• Since the dog is at home, stress doesn’t distort the glucose readings as it might in a clinic or hospital.
• Continuous glucose monitoring can provide nighttime readings, the period when the dog is most vulnerable to low blood sugar.

There are disadvantages. First, FreeStyle Libre is not calibrated for dogs. Second, it does not actually measure blood glucose levels. It measures interstitial glucose, that is, glucose levels in the tissue fluids, not the blood. These levels lag behind blood glucose levels.. Third, readings can be significantly different from AlphaTrak 2 glucometer readings, a blood glucose device that is calibrated for cats and dogs. Fourth, according to one study, it may not provide clinically accurate readings when the dog is hypoglycemic. Finally, the sensor may stop giving reliable glucose data. Failure is common with flash glucose monitoring systems like FreeStyle Libre.

For all these reasons, FreeStyle Libre is not a substitute for regular blood glucometer tests. The veterinarian will tell you when and how often to give the dog a stick test while the sensor is attached. As a general rule, if the FreeStyle Libre shows hypoglycemia, but the dog is okay, perform a blood test to be sure. If the FreeStyle Libre shows normal glucose levels but the dog is showing hypoglycemia symptoms, take a blood sample and check it with your home glucometer.

Is Freestyle Libre safe for dogs?

There is no safety data on FreeStyle Libre for dogs. The device has no contraindications when used for diabetes management in people. 

The greatest danger to the dog is when a well-meaning caregiver adjusts the insulin dose in response to the sensor’s glucose readings. This can cause serious or life-threatening problems. If readings are too low or too high, do not independently change the insulin dose until the veterinarian orders dose changes.

Side effects of Freestyle Libre in dogs

No veterinary study of FreeStyle Libre has reported serious side effects. In these studies, the only reported side effect in dogs was skin redness at the attachment site.

The most commonly reported side effects in people are:

• Skin redness
• Bruising
• Bleeding
• Scabbing

Interactions of Freestyle Libre with other pet meds

Although FreeStyle Libre does not affect pet meds, drugs or supplements given to the dog may alter sensor readings, particularly high doses of vitamin C.

Freestyle Libre dosage for dogs

As a medical device, FreeStyle Libre sensors do not have dosages. One requirement is that the pet owner take readings from the sensor every eight hours.

Can dogs overdose on Freestyle Libre?

Only one sensor should be used at a time. The smartphone app or monitoring device can only be linked to one sensor at a time. 

Can I give my dog Freestyle Libre every day?

The FreeStyle Libre sensor remains attached to the skin for 14 days or until it stops working.

How to give your dog Freestyle Libre

The FreeStyle Libre sensor is placed by a veterinary professional at a veterinary clinic. The pet parent’s main responsibilities are to download the smartphone app, take regular readings, and share those readings with the veterinarian.

FreeStyle Libre sensors, monitors, and apps are complex devices to use and operate. A veterinary professional will need to train you on the use of these devices. Read all of the supporting literature that comes packaged with the sensors.

Remember that Abbott will not provide customer service or technical help if the sensor is used on a companion animal. Talk to the veterinarian about what to do if there are technical problems scanning the sensor or using the app.

• Before sensor placement:
  • Talk to the veterinarian first.
  • Fill the prescription before the visit. You will bring the sensor with you to have it placed.
  • Download the smartphone app before the visit. 
  • You can also purchase a reader, but this is not advisable. It’s expensive and doesn’t allow you to upload data directly to the Internet. 
  • Read the entire user manual before the vet visit.
  • Set up the app on the phone before taking the dog to have the sensor placed. 
• Set up the app:
  • Open the app and follow the setup procedure. 
  • Create a LibreView account.
  • Share that account with the veterinarian. The veterinary clinic will provide instructions.
  • Don’t set alarms until you’ve talked to the veterinarian. They’re intended for people who can adjust their insulin administration, but you should not change your dog’s insulin dose.
• Placing the sensor:
  • A veterinarian or veterinary technician will place the sensor on your pet’s skin.
  • Bring the sensor to the appointment.
  • Bring the smartphone or reader to the appointment. Make sure your phone is on and the app is open before they place the sensor.
  • The sensor is usually placed on the dog’s back near the front shoulders. The surrounding area will be shaved. 
  • The sensor is usually attached to the skin with a skin adhesive, but a bandage may be added to keep it in place.
  • At this point, you will be asked to use the smartphone or reader to link the sensor to the app or reader. This should be finished in the clinic rather than at home.
• After the sensor is placed:
  • You must scan the sensor at least every eight hours. 
  • Make sure the phone has Bluetooth turned on.
  • Make sure the app is open.
  • Hold the back of the phone near the sensor. An Android phone will automatically scan the sensor and sound twice when finished. To scan with an Apple phone, press the scan button in the app. 
  • The data will automatically upload to your LibreView account from the smartphone.
  • The dog may dislodge the sensor or remove it entirely. Immediately call the veterinarian if this happens. Do not try to adjust a dislodged sensor or reattach a sensor that has been removed. Do not put a new sensor on the dog.
  • If the data shows the dog is hypoglycemic or shows signs of hypoglycemia, perform a blood test. If the blood test shows hypoglycemia, call the veterinarian or a veterinary hospital.
  • Never adjust the dog’s insulin dose. Only change the dose when instructed to do so by a veterinarian.
• When the sensor comes off:
  • Ask the veterinarian what to do when a sensor needs to come off.
  • In most cases, pet caregivers can remove the sensor themselves or have a vet tech do it.
  • The sensor should be removed in 14 days. Even if it can still be scanned, the data is not reliable.
  • The sensor should be removed if it gets moved, loosens, or fails to scan. Failure is common in CGM sensors, so it may not last the entire 14 days.

Freestyle Libre alternatives for dogs

The FreeStyle Libre system is a flash glucose monitoring system. Some veterinarians may use a comparably priced system, the Dexcom G7, but it is not as well-studied in companion animals as the FreeStyle Libre.

The primary alternative is a blood glucose curve, an in-hospital procedure monitoring the dog’s blood glucose concentrations over 10 or 12 hours. Caregivers also have the option of doing this at home, but veterinarians don’t consider the results to be reliable.

Summary

FreeStyle Libre is a continuous glucose monitor that helps veterinarians assess and adjust insulin treatment in diabetic dogs. They use it to replace the standard blood glucose curves that require the pet to spend 10 or 12 hours in a clinic or hospital. Some veterinarians prefer using the FreeStyle Libre because of the richness of the data it provides. Used under the direction of a veterinarian, FreeStyle Libre glucose monitoring is safe for dogs.