Cat Diabetes: Blood Sugar Levels, Monitoring, and Management

Cat diabetes affects 1 in 200 cats, often developing after age 8. Key signs: excessive thirst, urination, weight loss despite increased appetite. Target glucose: 100-250 mg/dL. With proper management, 30% of cats can achieve remission.

If your cat is suddenly drinking gallons of water and using the litter box constantly, diabetes could be the cause. The good news? Cat diabetes is highly manageable, and many cats can even achieve remission with proper care.

Understanding Cat Diabetes

Diabetes in cats occurs when the pancreas doesn't produce enough insulin or the body becomes resistant to insulin. Without insulin, glucose builds up in the bloodstream instead of entering cells for energy.

Most cats develop Type 2 diabetes, similar to human adult-onset diabetes. Unlike dogs (who typically get Type 1), cats have a much better chance of remission with early, aggressive treatment.

Recognizing Diabetes Symptoms

Classic Early Signs

• Excessive thirst (polydipsia) — Constantly drinking water
• Frequent urination (polyuria) — Large amounts of urine, more litter box trips
• Increased appetite — Eating more but still losing weight
• Weight loss — Despite increased food intake
• Lethargy — Less active, sleeping more

Advanced Signs (More Serious)

• Poor coat condition — Dull, greasy, or unkempt fur
• Muscle wasting — Loss of muscle mass, especially hind legs
• Weakness — Difficulty jumping or walking normally
• Frequent infections — Especially urinary tract infections
• Sweet-smelling breath — May indicate diabetic ketoacidosis
• Vomiting and dehydration — Signs of diabetic crisis

🚨 Emergency Signs:

Vomiting, lethargy, difficulty breathing, or sweet breath odor can indicate diabetic ketoacidosis — a life-threatening emergency requiring immediate veterinary care.

Blood Glucose Levels and Testing

Understanding Glucose Ranges

Glucose Level	Range (mg/dL)	Interpretation
Normal	74-159	Healthy cat, no diabetes
Stress hyperglycemia	200-250	May be stress-related, repeat testing needed
Diabetic	250-600+	Diabetes diagnosis, treatment needed
Target (treated)	100-250	Good control with insulin therapy
Hypoglycemia	Under 70	Too much insulin — emergency
Critical high	Over 400	Risk of ketoacidosis — urgent care

Diagnostic Tests

Fasting Blood Glucose: Single blood test after 12-hour fast. Values over 250 mg/dL typically confirm diabetes.

Fructosamine: Measures average glucose over 2-3 weeks. More reliable than single glucose measurements for diagnosis.

Urine Glucose: Glucose spills into urine when blood levels exceed ~200 mg/dL. Useful for monitoring at home.

Complete Bloodwork: Checks for complications and concurrent diseases. Learn more about interpreting cat blood test results.

Insulin Therapy and Management

Types of Insulin for Cats

Glargine (Lantus): Long-acting insulin, often first choice. Administered every 12 hours.

Detemir (Levemir): Another long-acting option with similar efficacy to glargine.

ProZinc: FDA-approved insulin specifically for cats and dogs. Good option for many diabetic cats.

Injection Schedule and Technique

• Timing: Give insulin every 12 hours with meals
• Location: Rotate injection sites along the back and sides
• Technique: Lift skin, insert needle, inject slowly
• Storage: Keep insulin refrigerated, never freeze
• Safety: Always feed before giving insulin to prevent hypoglycemia

Need help tracking your diabetic cat's glucose levels?

Upload your cat's blood glucose results to VetLens for trend analysis, insulin dosing insights, and personalized diabetes management recommendations.

Track Glucose Trends

Home Monitoring Strategies

Glucose Curve Monitoring

A glucose curve tracks blood sugar levels throughout the day to assess insulin effectiveness. Typically performed every 3-6 months once stable.

How it works: Measure glucose every 2 hours from morning insulin injection to evening injection (12-hour period).

Daily Monitoring Options

Home glucose testing: Use human glucometers with cat-calibrated strips. Test ear or paw pad.

Urine glucose strips: Less stressful alternative. Glucose in urine indicates blood levels over 200 mg/dL.

Continuous glucose monitors: FreeStyle Libre sensors can be applied to cats for 14-day monitoring.

What to Watch For

• Hypoglycemia signs: Weakness, lethargy, seizures, loss of coordination
• High glucose symptoms: Return of excessive thirst and urination
• Appetite changes: Loss of appetite may indicate illness or poor glucose control
• Weight changes: Monitor weekly; weight loss may indicate poor control

Diet and Lifestyle Management

Diabetic Diet Principles

• High protein, low carbohydrate: Target less than 10% carbohydrates
• Consistent feeding schedule: Feed same amount at insulin injection times
• Weight management: Achieve and maintain ideal body weight
• Prescription diets: Hills m/d, Royal Canin Diabetic, or similar veterinary diets

Exercise and Environment

• Consistent routine: Keep exercise levels steady day to day
• Indoor lifestyle: Reduces stress and allows better monitoring
• Stress reduction: Minimize changes in environment or routine
• Regular veterinary care: Monitor for complications like dental disease or infections

Achieving Remission

What is Diabetic Remission?

Diabetic remission means maintaining normal blood glucose levels without insulin injections for at least 4 weeks. Up to 30% of diabetic cats can achieve remission with proper management.

Factors That Improve Remission Chances

• Early diagnosis and treatment: Best outcomes when treated within first few months
• Optimal insulin therapy: Achieving target glucose ranges consistently
• Weight loss: Returning to ideal body weight reduces insulin resistance
• Low-carb diet: Reduces glucose spikes and insulin requirements
• Treatment of concurrent disease: Managing dental disease, infections, other conditions

Monitoring for Remission

Signs of remission include consistently normal glucose levels, resolution of diabetes symptoms, and ability to maintain normal glucose without insulin. Your vet will guide the process of tapering insulin doses.

Complications and Emergency Care

Diabetic Ketoacidosis (DKA)

DKA is a life-threatening complication when the body breaks down fat for energy, producing toxic ketones.

Signs: Vomiting, lethargy, dehydration, sweet breath odor, difficulty breathing. Requires immediate emergency treatment.

Hypoglycemia (Low Blood Sugar)

Usually caused by too much insulin, delayed meals, or increased activity.

Emergency treatment: Rub corn syrup on gums if conscious, give small meal if alert. Contact vet immediately.

Long-term Complications

• Kidney disease: Diabetes can accelerate kidney damage. Monitor with regular kidney function tests
• Cataracts: Less common in cats than dogs, but can occur
• Infections: Diabetic cats are prone to urinary tract and other infections
• Neuropathy: Nerve damage causing weakness in hind legs

Prognosis and Quality of Life

Life Expectancy

With proper management, diabetic cats can live normal lifespans. Many cats live 5+ years after diagnosis, and some achieve complete remission.

Success depends on early diagnosis, consistent treatment, owner compliance, and achieving good glucose control.

Quality of Life Considerations

• Daily injections: Most cats adapt well to insulin shots
• Dietary changes: Prescription diets are usually well-accepted
• Monitoring: Regular vet visits and home monitoring required
• Cost: Ongoing expenses for insulin, monitoring supplies, and veterinary care

Track Your Diabetic Cat's Progress

Upload your cat's glucose results into VetLens and get:

✓ Glucose trend analysis and insulin effectiveness tracking
✓ Remission probability assessment based on current control
✓ Early detection of complications through bloodwork monitoring
✓ Personalized diet and insulin adjustment recommendations

Start Tracking Today

Frequently Asked Questions

What are normal blood glucose levels for cats?

Normal blood glucose levels for cats range from 74-159 mg/dL. Diabetic cats typically have glucose levels above 250-300 mg/dL when diagnosed.

What are the early signs of diabetes in cats?

Early signs include increased thirst and urination, increased appetite with weight loss, lethargy, and poor coat condition. Many cats also develop urinary tract infections.

How often should I check my diabetic cat's blood sugar?

During initial stabilization, check glucose 1-2 times daily. Once stable, most cats need glucose curves every 3-6 months, with daily monitoring at home as needed.

Can cat diabetes go into remission?

Yes, up to 30% of diabetic cats can achieve remission with proper treatment, especially if diagnosed early. Remission means normal glucose levels without insulin injections.

What should I do if my cat's blood sugar is too high?

If glucose is over 400 mg/dL or your cat shows symptoms like vomiting, lethargy, or difficulty breathing, contact your vet immediately. This can indicate diabetic ketoacidosis, a life-threatening emergency.