🩺 Diabetes Mellitus in Dogs & Cats – A Complete 2025 Vet Guide

By Dr Duncan Houston, BVSc

🔍 What Is Diabetes Mellitus?

Diabetes mellitus is a condition caused by a deficiency of insulin—a hormone produced by the pancreas that allows sugar (glucose) to enter the cells of the body. Without insulin, sugar remains in the bloodstream, leading to dangerously high blood glucose levels. 🧪

📌 In dogs:

Diabetes is usually insulin-dependent and lifelong. Insulin injections are required. 💉

📌 In cats:

Some cats may eventually go into remission, especially with early insulin support and dietary changes. 🐱

⚠️ Symptoms of Diabetes in Pets

The classic signs of diabetes are:

• 🚰 Excessive thirst (polydipsia)
• 💦 Excessive urination (polyuria)
• 🍽️ Increased appetite (polyphagia)
• ⚖️ Unexplained weight loss

Other signs can include fatigue, frequent urinary infections, cataracts in dogs, and a poor coat. 💧

🔬 How Diabetes Affects the Body

Without insulin, the body’s cells can’t use sugar for energy. Glucose builds up in the blood and spills into the urine. This creates a cycle:

• 💥 Sugar in the urine draws out water → excessive urination
• 💧 Loss of water → excessive thirst
• 💪 Starved cells → fat/muscle breakdown → weight loss
• 🥺 Constant hunger → increased appetite

👁️ Diabetes and Cataracts (in Dogs)

In diabetic dogs, high glucose in the eye lens turns into sorbitol, which draws in water and clouds the lens—this leads to diabetic cataracts and often, blindness. 🐕👁️

💉 Treating Diabetes: Insulin Therapy

Most pets with diabetes will need insulin injections. Don’t worry—it’s easier than it sounds. Here's what to expect:

🧪 Getting Started:

• 🧮 Starting dose is based on weight & blood sugar averages
• ⚙️ Dose adjusted over time based on results and symptom control

🛠️ Types of Insulin Delivery:

• Syringes: Draw insulin from a vial and inject manually
• Insulin Pens: Dial a dose and inject using a pre-filled pen (may require specific tips for pets)

⏱️ Frequency:

Most pets receive injections twice a day, 12 hours apart, timed with meals. 🕛

🍽️ Diet and Feeding Strategies

For Dogs 🐶:

• ✅ High fiber, low fat
• 🍽️ Two consistent meals daily, timed with insulin
• 🚫 Avoid sugary treats and table food

For Cats 🐱:

• ✅ High protein, low carbohydrate
• 🧴 Free feeding preferred (access to food at all times)
• 🍖 Canned or prescription diets are often best

💊 Oral Medications for Cats

Some cats may qualify for oral glucose-lowering drugs:

• Bexagliflozin – Helps eliminate glucose via the kidneys
• Velagliflozin – Liquid form with similar effects
• Glipizide – Stimulates insulin production from beta cells (less effective, fewer risks)

Note: These are not a substitute for insulin in many cases and require careful vet supervision. 🩺

🧪 Monitoring Glucose Levels

📉 Home Glucose Testing Methods:

• Continuous Glucose Monitor (CGM): Implantable sensor like FreeStyle Libre; sends real-time glucose readings to your phone or vet 📲
• Glucometer: Measures drops of blood from ear or paw 🩸

Track readings, meals, and insulin administration in a log or app. Bring this data to vet visits. 📔

🚨 Recognizing Hypoglycemia (Low Blood Sugar)

This is the most urgent complication. It happens if:

• Too much insulin is given
• Your pet doesn't eat before an injection

⚠️ Signs Include:

• 😴 Lethargy
• 🌀 Staggering or drunkenness
• 🥴 Weakness or trembling
• ⚡ Seizures or collapse

💡 What To Do:

Rub honey or corn syrup on gums (1 tbsp per 5 lbs). Call your vet or go to the emergency clinic immediately. 🚑

📅 When to Recheck or Adjust Treatment

Bring your pet in if you notice:

• 📉 Weight loss
• 🥵 Increased thirst or urination
• 🍽️ Appetite changes
• 🧠 Disorientation or collapse

Dental health is also crucial—tartar and infection can destabilize glucose levels. 🦷

📉 Hard-to-Regulate Diabetes

Some pets may not respond predictably to insulin. Possible reasons include:

• ⚠️ Improper injection technique
• ⏱️ Rapid insulin metabolism
• 📈 Insulin overdose causing rebound hyperglycemia
• 💊 Steroid or hormone interference (e.g., unspayed females)

Work closely with your vet to make adjustments. Your pet may need a different insulin type or dosing schedule. 🧠

📲 Ask A Vet for Diabetic Pet Support

Diabetes can feel overwhelming at first—but with training, monitoring, and consistent routines, you’ll quickly become an expert in your pet’s care. 🐾

Need help with glucose logs, dose adjustments, or insulin techniques? The Ask A Vet App offers 24/7 access to veterinary advice, tools, and medication reminders. Visit AskAVet.com today. 🐶📱

✅ Summary: Key Takeaways

• 📌 Diabetes is caused by a lack of insulin
• 💉 Most pets need twice-daily insulin injections
• 🍽️ Diet and feeding strategies vary for dogs vs. cats
• 📊 Monitoring at home improves regulation and saves money
• 🚨 Hypoglycemia is an emergency—know the signs!
• 🧠 Some pets are difficult to regulate and need tailored care

💬 Final Words from Dr Duncan Houston

Diabetes isn’t a sentence—it’s a call to action. With patience and partnership, your diabetic dog or cat can live a long, happy life. Remember to check in with your vet regularly, use home tools to monitor progress, and never hesitate to ask for help. 🐶🐱💙

Need guidance right now? Tap into expert support with the Ask A Vet App or visit AskAVet.com. Together, we’ll keep your best friend healthy and thriving. 🐾📱