💉 Insulin Administration in Dogs – A 2025 Vet's Guide to Delivery, Dosing & Storage

By Dr Duncan Houston, BVSc

🔍 What Is Insulin and Why Is It Needed?

Insulin is the essential hormone used to control blood glucose in diabetic dogs. Since the pancreas no longer produces enough insulin naturally, injections are needed to prevent complications like weight loss, excessive thirst, and diabetic ketoacidosis. 🩺

📆 How Often Are Injections Given?

Most diabetic dogs require insulin twice daily, 12 hours apart. A few may do well on once-daily doses, but this is rare. Your vet will start with an initial dose and adjust it after monitoring blood glucose trends. 📈

🩸 Monitoring Blood Sugar

• 🏥 Glucose curves can be done in the clinic every 2 hours
• 📱 Home options include the FreeStyle Libre® or handheld glucometers
• 💬 Results can be shared with your vet to adjust dosing

💊 Types of Insulin Used in Dogs

• Vetsulin® (U-40, veterinary, pork-derived)
• Humulin N® / Novalin N® (U-100, human insulin)
• ProZinc® (U-40, veterinary insulin)
• Glargine insulin (U-100, human, longer-acting)

🐾 Veterinary and human insulins differ in strength and origin—use the correct syringes! Never switch without veterinary guidance. ❗

🧊 Insulin Storage Tips

• ✅ Store insulin in the refrigerator (but not frozen)
• ☀️ Keep away from light and heat
• 📅 Use opened insulin within 6–8 weeks (up to 4–6 months if properly refrigerated—check with your vet)
• ❌ Discard insulin that’s discolored, cloudy (unless it’s supposed to be), or expired

🧪 Syringe Dosing and Injections

Insulin Concentration and Syringe Match:

• U-40 insulin → U-40 syringe
• U-100 insulin → U-100 syringe

🖐️ Injection Technique:

1. 🎯 Use the shoulder blade area
2. ⏱️ Change injection sites daily (alternate left and right)
3. 📍 Draw insulin with bottle held upside down
4. 💉 Remove air bubbles by tapping the syringe
5. 🐶 Gently lift a skin fold and insert the needle under the skin
6. ✅ Inject and remove the needle smoothly

Most dogs don’t react to the needle—but still may resist being held. Use a calm tone and treats. 🦴

🔐 Safe Disposal of Syringes

• 🧴 Use a thick plastic container like a detergent bottle
• ♻️ Return used syringes to your vet or use proper sharps disposal per your state

🖊️ Using Insulin Pens

Advantages:

• ✅ Accurate dosing—down to half units
• 💡 Easy push-button delivery
• ⏱️ No need to draw insulin manually

Tips:

• 📌 Prime before use
• 📍 Hold needle in place for 5 seconds after pressing
• 🧴 Use a new needle tip each time

⚠️ Storage Notes:

• 🚫 Pens should not be refrigerated once in use—store at room temp (use within 6 weeks)
• 🧊 Keep extra cartridges refrigerated (not frozen)

🥗 Feed Before You Inject

Always feed your dog before giving insulin (except in special cases like with Novalin N® which may be given before meals—check with your vet). 🐶🍽️

If your dog doesn’t eat, don’t give insulin and contact your vet immediately. You may risk dangerously low blood sugar. ⚠️

📈 What to Expect Over Time

• ⏳ Injections become easier with practice
• 🧠 Your confidence will grow quickly
• 🤝 Your vet is always there to help with adjustments and support

📲 Ask A Vet for Insulin Support

Whether you're just starting or adjusting an ongoing insulin plan, the Ask A Vet App gives you direct access to veterinary experts 24/7. 🐾💉

Send in glucose readings, ask about injection technique, and get help with dosing decisions between visits. Visit AskAVet.com or download the app today. 🩺📱

✅ Summary: Key Tips

• 💉 Use the correct syringe for your insulin type
• 🥶 Store insulin refrigerated (don’t freeze)
• 🍽️ Feed before injecting (unless instructed otherwise)
• 📈 Monitor blood sugar at home or with your vet
• 🗓️ Replace insulin every 6–8 weeks (or per vet instructions)
• ♻️ Dispose of needles safely

💬 Final Words from Dr Duncan Houston

Giving insulin to your dog might seem intimidating at first—but with a little practice and patience, it becomes second nature. With proper storage, accurate dosing, and regular vet check-ins, you’re giving your dog the best chance at a healthy, happy life. 🐶❤️

Have questions? Don’t hesitate to reach out through the Ask A Vet App or visit AskAVet.com. We’re here to support you and your dog every step of the way. 📱🩺