Cat Diabetes Management Guide | Symptoms, Diagnosis, Insulin Administration, and Practical Dietary Therapy

What is Feline Diabetes

Feline diabetes is a metabolic disorder in which blood glucose levels become chronically elevated due to either insufficient insulin secretion from the pancreas or increased insulin resistance in tissues. Feline diabetes is primarily Type 2 (insulin resistance type), and like in humans, obesity, high-carbohydrate diet, aging, and lack of exercise are the main contributing factors.

With early detection, appropriate treatment, and dietary management, it is possible to achieve "remission"—a state in which insulin administration is no longer necessary—in some cases.

Signs and Symptoms of Diabetes

If multiple symptoms below are present, diabetes may be a possibility.

• Polydipsia and polyuria: Drinking water frequently and increased urination (most typical initial symptoms)
• Weight loss: Despite good appetite, weight decreases
• Lethargy: Decreased activity and increased listlessness
• Dull coat: Loss of coat shine
• Hind limb weakness: Walking with dropped hocks, characteristic of "diabetic peripheral neuropathy"

If left untreated, it can progress to diabetic ketoacidosis (DKA), a life-threatening condition, so immediate veterinary care is essential if symptoms are detected.

Diagnosis and Reading Blood Test Results

The following tests are performed to diagnose feline diabetes.

Blood Glucose (Glucose)

Diabetes is suspected when fasting blood glucose levels of 250 mg/dL or higher are confirmed multiple times. However, cats may experience "stress-induced hyperglycemia" with levels of 250–400 mg/dL, so diagnosis is not made on a single blood glucose measurement alone.

Fructosamine (Fructosamine)

An indicator that reflects average blood glucose levels over the past 2–3 weeks. It is not affected by stress and is important for confirming diabetes diagnosis. Levels of 370 μmol/L or higher strongly suggest diabetes.

Urinalysis

Glucose in urine (glucosuria) is often positive, but cats may also show glucosuria due to stress. If ketones are present in the urine, there is a risk of DKA, indicating high urgency.

Fundamentals of Insulin Therapy

Types of Insulin

Commonly used insulins in cats include "Prozinc insulin (PZI)," "Glargine (Lantus)," and "NPH insulin (Novolin N)." In Japan, veterinarians primarily prescribe Prozinc or Glargine.

Dosage and Frequency

Initial dosing is typically 0.1–0.5 units per kilogram of body weight twice daily, but always follow your veterinarian's instructions. Insulin doses are adjusted regularly based on blood glucose monitoring.

Insulin Administration Procedure at Home

1. Use an insulin pen or syringe (28–29 gauge needle)
2. Subcutaneous injection: The back of the neck, area between shoulder blades, and lower back are convenient injection sites
3. Pinch the skin and insert the needle at a 45–90 degree angle
4. Slowly inject, then withdraw the needle
5. Rotate injection sites slightly each time (repeated injections in the same location cause skin to become firm)
6. Timing around meals: Administration immediately after the cat eats is typical (on days when the cat has poor appetite, reduce the dose or consult your veterinarian)

Home Blood Glucose Monitoring

Home glucose measurement is the most effective method to significantly improve treatment management accuracy.

Equipment: Human blood glucose meters can be used as a substitute, but calibration for cats is necessary so consult your veterinarian. AlphaTrak (for cats and dogs) is most commonly used.

Blood sampling sites: The outer ear or paw pads are common sites. Warming the ear makes blood vessels more accessible.

Target blood glucose levels (if aiming for remission):

• Before meals: 80–150 mg/dL
• 2–4 hours after meals (peak time): Ideally 200 mg/dL or less

Beware of hypoglycemia: Blood glucose levels of 50 mg/dL or below cause hypoglycemic symptoms (wooziness, seizures, loss of consciousness). Immediately apply honey or sugar to the gums and seek emergency care.

Dietary Therapy: High-Protein, Low-Carbohydrate Diet

Cats are obligate carnivores and have limited ability to metabolize carbohydrates. High-protein, low-carbohydrate diets with minimal carbohydrates are recommended for diabetic cats.

Recommended diets

• Wet food (canned or pouched): Low carbohydrate and high moisture content
• High-protein prescription diets (Hills m/d, Royal Canin Glycobalance, etc.)
• Home-cooked meals (primarily chicken breast and fish; however, always supplement with feline-specific vitamins to maintain nutritional balance)

Foods to avoid

• Dry food (high carbohydrate): Generally not recommended for diabetic cats
• High-sugar treats

Remission Potential and Long-Term Management

Remission can be achieved within several months of starting appropriate treatment in some cases. Factors that increase the probability of remission include:

• Early diagnosis and early initiation of treatment
• Weight normalization (obesity resolution)
• Complete transition to low-carbohydrate, high-protein diet
• Use of glargine-based insulin

Regular blood tests (every 3–6 months) to confirm fructosamine and blood glucose levels, with insulin doses reviewed and adjusted as needed, form the foundation of long-term management.

Summary

The timing of detection and treatment determines whether remission is possible for feline diabetes. When you notice signs of increased drinking and urination or weight loss, seek veterinary care early. After diagnosis, manage the condition with a three-pronged approach: insulin administration, low-carbohydrate diet, and blood glucose monitoring. Establishing a routine of home blood glucose testing significantly improves treatment accuracy.