📈 Flash Glucose Monitoring in Dogs and Cats – A 2025 Vet’s Guide to Using FreeStyle Libre

By Dr Duncan Houston, BVSc

🔬 What Is Flash Glucose Monitoring?

Flash glucose monitoring, also known as continuous glucose monitoring (CGM), allows pet parents to monitor diabetic pets’ glucose levels easily and painlessly at home. 🧪

The FreeStyle Libre system is currently the most widely used CGM tool for pets—even though it’s designed for humans. Veterinarians have gained valuable experience using it with cats and dogs to monitor interstitial (under the skin) glucose levels. 🐾

⚠️ Note: FreeStyle Libre is not officially approved for animal use. Abbott, the manufacturer, does not provide technical support or warranty replacement for pet usage.

📲 How Does the FreeStyle Libre Work?

The FreeStyle Libre uses a sensor with a small, flexible catheter that is inserted under the skin. The sensor records glucose levels in the interstitial fluid (not blood). While values may differ slightly from blood glucose, they are accurate enough for monitoring diabetes at home. 📊

Key Features:

• 📆 14 days of continuous data per sensor
• 📡 Wireless data readout via reader or smartphone
• 💉 No painful blood pricks required

⚙️ How Is the Sensor Implanted?

Your vet will place the sensor in a flat, low-motion area on your pet's back. The sensor is small—about the size and thickness of two stacked quarters. 📏

Implantation Steps:

• ✂️ Area shaved and cleaned
• 📦 Sensor pressed into place using an applicator
• 😌 Most pets don't even notice the implantation

🧠 Where to Place the Sensor

Placement is key to keeping the sensor in place. Ideal areas are:

• Flat and low-motion zones (e.g., upper back)
• Out of reach of mouth or paws 🐾
• At least 1 inch away from insulin injection sites 💉

Tips to keep the sensor on longer:

• 🛡️ Use a pet T-shirt or stockinette to cover it
• 🚫 Avoid scratching or biting with an E-collar

🛒 Where to Get It

Your vet can write a prescription. Each sensor lasts up to 14 days. You’ll need a reader or compatible smartphone (iPhone 7 or newer with app). Only use one device to scan the sensor—using multiple readers may lead to data gaps. 📱

📶 Reading the Data

Glucose is recorded automatically, but for complete records, you must scan the sensor at least every 8 hours. Skipping scans results in data loss. 📊

Your vet will walk you through uploading the data for review. Plan ahead—set up your account and data-sharing method before activating the sensor. 📤

📈 How It Helps Adjust Insulin

With 24/7 glucose patterns available, your vet can:

• ⚖️ Adjust insulin doses in real time
• 📆 Make 1–2 dose changes within one sensor cycle
• 😺 View non-stress readings at home vs. in-clinic

Cost vs. Value:

Even if the sensor only lasts 5 days (vs. 14), the cost is comparable to a single hospital glucose curve—but with better accuracy and comfort. 💵📉

🧪 Understanding Hypoglycemia Warnings

Flash glucose monitors aren’t always perfect in pets:

• If the system shows low glucose but your pet is acting normal: ✅ Double-check with a glucometer
• If your pet shows hypoglycemic symptoms (e.g., wobbling, weakness, seizures) but the system reads normal: ❗Check with a glucometer

⚠️ Always verify abnormal readings with a veterinary glucose meter if your pet seems unwell. 🩺

🐶 Advantages for Dogs

• 📈 Better insulin dose adjustments
• 🏡 Stress-free monitoring at home
• 👃 Reduces need for ear or paw pricks

🐱 Advantages for Cats

• 📉 Prevents white-coat stress spikes
• 🧘 Accurate data in natural environment
• 🔁 Easier monitoring for tricky cases

📋 Summary: Key Benefits of FreeStyle Libre in Pets

• 💡 Simple, painless sensor placement
• 📲 14 days of detailed glucose data
• ⚙️ iPhone or dedicated reader for tracking
• 📈 Enables better insulin control
• 📉 Reduces pet stress and hospital visits

📲 Ask A Vet for Glucose Monitoring Support

Using a FreeStyle Libre with your diabetic dog or cat can make diabetes care more precise and less stressful. Need help interpreting the graphs or setting up data sharing?

Get personalized support through the Ask A Vet App or at AskAVet.com. With expert guidance, you’ll confidently use technology to improve your pet’s health. 🐾💙

💬 Final Words from Dr Duncan Houston

Technology is revolutionizing pet care. Flash glucose monitoring offers game-changing insights that empower both pet parents and vets. If your pet has diabetes, the FreeStyle Libre may be your new best friend. 🐶📊🐱

For expert advice and step-by-step help, open the Ask A Vet App or visit AskAVet.com. Let’s make diabetic care easier—together. 🩺📱