The Role of Insulin

Insulin, a hormone produced by the pancreas, is essential for life. It performs several critical functions:

• Facilitates the entry of glucose into cells to be used for energy
• Regulates and stabilizes blood sugar levels
• Promotes the storage of fat and protein

Without effective insulin, cells are starved of energy despite an abundance of glucose in the bloodstream. The body is forced to break down fat and muscle tissue for fuel, leading to weight loss and other complications.

Types of Feline Diabetes

Type 2 Diabetes (90-95% of Cases)

Characteristics:

• Insulin resistance: The body's cells do not respond properly to insulin.
• Strong link to obesity: Excess body fat is a major contributing factor.
• Relative insulin deficiency: The pancreas may produce insulin, but it is ineffective.
• Potential for remission: This form is often reversible with aggressive early management, including weight loss and dietary change.

Type 1 Diabetes (5-10% of Cases)

Characteristics:

• Absolute insulin deficiency: The insulin-producing beta cells in the pancreas are destroyed.
• Lifelong insulin dependence: These cats require exogenous insulin therapy for life.
• No remission possible: The damage to the pancreas is permanent.

Transient Diabetes

Definition: A temporary diabetic state that resolves after initial treatment.

• Common causes: Other illnesses (like pancreatitis), steroid medication, or severe stress can induce transient high blood sugar.
• Important note: Even after resolution, these cats remain at higher risk for developing permanent diabetes later in life and require ongoing monitoring.

Risk Factors

Primary Risk Factors

Breed Predispositions

Contributing Medical Conditions

Several concurrent diseases can trigger or worsen diabetes:

• Pancreatitis: Inflammation damages insulin-producing cells.
• Hyperthyroidism: Accelerates metabolism and can cause insulin resistance.
• Cushing's Disease (Hyperadrenocorticism): Excess cortisol induces severe insulin resistance.
• Long-term Steroid Use: A common cause of drug-induced diabetes.
• Acromegaly: Excess growth hormone causes profound insulin resistance.

Symptoms and Early Warning Signs

The Four Classic Clinical Signs (The "Polys")

1. Polyuria (Excessive Urination)

• Noticeably larger clumps in the litter box or more frequent box use.
• Urinating outside the litter box due to urgency.
• The body attempts to flush excess glucose through the kidneys.

2. Polydipsia (Excessive Thirst)

• Water bowls are emptied rapidly.
• Cat seeks new water sources (faucets, toilets, pet water fountains).
• Drinking is a compensatory response to fluid loss from polyuria.

3. Polyphagia (Excessive Hunger)

• Ravenous appetite despite eating normal or increased amounts.
• Constant begging, meowing for food, or food stealing.
• Cells are starving for glucose, signaling the brain to eat more.

4. Weight Loss

• Loss of muscle and fat despite a good or increased appetite.
• The body breaks down its own tissues for energy in the absence of usable glucose.
• Hind-end muscle wasting may be particularly noticeable.

Additional Symptoms and Complications

Diabetic Neuropathy

This is nerve damage caused by prolonged exposure to high blood glucose levels.

• Symptoms: Weakness in the hind legs, difficulty jumping, a "plantigrade" stance (walking with the hocks touching the ground), and poor coordination.
• Hope for Recovery: Unlike many neuropathies, diabetic neuropathy can significantly improve or even resolve once blood glucose levels are brought under stable control.

Diagnosis

Key Diagnostic Tests

1. Blood Glucose Testing

• Normal feline range: 80-120 mg/dL (4.4-6.7 mmol/L).
• Suggestive of diabetes: Consistently >250-300 mg/dL (13.9-16.7 mmol/L), especially if fasting.
• Important Caveat: "Stress hyperglycemia" can temporarily elevate a healthy cat's glucose to 300-400 mg/dL during a vet visit.

2. Fructosamine Test

• Measures the average blood glucose level over the preceding 2-3 weeks.
• Not affected by short-term stress, making it crucial for confirming a diabetes diagnosis.
• High fructosamine confirms chronic hyperglycemia.

3. Urinalysis

• Glucosuria: Detection of glucose in the urine is a key diagnostic finding.
• Ketones: Their presence is a red flag for Diabetic Ketoacidosis (DKA).
• Urinary Tract Infection (UTI) Check: Diabetic cats are prone to UTIs because sugar in the urine promotes bacterial growth.

4. Additional Recommended Testing

Diagnosing Diabetic Ketoacidosis (DKA)

DKA is a life-threatening metabolic crisis requiring immediate hospitalization.

• Diagnostic Triad:
  1. Hyperglycemia (usually >400 mg/dL)
  2. Ketosis (ketones in blood and urine)
  3. Acidosis (blood pH <7.3)
• Symptoms: Lethargy, anorexia, vomiting, dehydration, and collapse.

Treatment Options

Insulin Therapy: The Cornerstone of Treatment

Common Insulin Types for Cats (2026):

Note: Glargine (Lantus) is often the insulin of choice in modern protocols due to its association with the highest rates of diabetic remission.

Insulin Administration Tips:

• Given via subcutaneous (under the skin) injection.
• Common sites: The scruff or the flank.
• Rotate injection sites to prevent lipodystrophy (lumpy scar tissue).
• Use ultra-fine needles (e.g., 31-gauge) - most cats feel little to no discomfort.
• Golden Rule: Never change the insulin dose without explicit guidance from your veterinarian.

Dietary Management: Food as Medicine

Dietary Goals for Diabetic Cats:

• Low Carbohydrate (<10% of calories from carbs)
• High Protein (40-50% of calories)
• Moderate Fat (35-45% of calories)
• Consistent Feeding Schedule (timed with insulin injections)

Recommended Food Categories:

Feeding Schedule:

• Ideal: Feed a measured meal at the time of each insulin injection.
• Alternative: If using a very long-acting insulin, some cats can do well with free-choice feeding of a low-carb diet, but this requires careful monitoring.

Oral Medications (Limited Role)

• Glipizide: An oral sulfonylurea that stimulates the pancreas to release insulin.
• Use: Only considered in very mild, early cases where the owner absolutely cannot give injections.
• Reality: It is rarely effective as a sole therapy, has side effects (vomiting, liver issues), and does not promote remission. Insulin is the standard of care.

Home Monitoring: Your Key to Success

Blood Glucose Monitoring

Choosing a Glucometer:

• AlphaTRAK 3: Veterinarian-recommended; calibrated specifically for cats and dogs.
• Freestyle Libre: A continuous glucose monitor (CGM) sensor placed on the skin; provides trends without daily ear sticks.
• Human Glucometers: Can be used but often read 15-20% lower than a pet-specific meter. Consistency in using the same meter is key.

How to Perform a Blood Glucose Test:

1. Warm the site (ear margin or paw pad) with a warm cloth.
2. Prick with a sterile lancet.
3. Collect the small blood drop on the test strip.
4. Record the reading with the date and time.

Target Blood Glucose Ranges:

The Glucose Curve

A "curve" involves testing blood glucose every 1-2 hours over a 12-hour period (e.g., from one insulin injection to the next).

• Purpose: To see the insulin's peak effect, duration, and the blood sugar's lowest point (nadir).
• Frequency: Weekly when starting or adjusting insulin; monthly for stable cats.
• This is the most valuable tool for your vet to safely optimize the insulin dose.

Cost of Treatment

Initial Diagnosis & Setup (Estimated)

Monthly Ongoing Costs (Estimated)

Annual Cost Perspective & Savings Tips

• Year 1: $3,000 - $7,000 (includes diagnosis, stabilization, and initial supplies).
• Subsequent Years: $2,500 - $6,000 for stable management.
• Cost-Saving Strategies:
  • Purchase insulin in larger vial sizes (e.g., 10mL vs. 2.5mL).
  • Buy syringes and test strips in bulk from reputable online pharmacies (with vet approval).
  • Pet Insurance: This is most valuable if obtained before a diabetes diagnosis. It can cover a significant portion of ongoing costs.

Achieving Remission: The Goal

What is Diabetic Remission?

Remission occurs when a cat maintains normal blood glucose levels without the need for insulin injections. It is not a "cure," but a treatment-free state.

• Clinical Remission: No insulin needed, but diet management continues.
• Complete Remission: Normal blood sugar without dietary restrictions (rare).

Remission Rates and Factors

The Remission Protocol

The "Tight Regulation" Approach:

1. Start immediately with twice-daily glargine (Lantus) insulin.
2. Transition exclusively to a low-carbohydrate, high-protein canned diet.
3. Implement home glucose monitoring, performing curves 1-2 times per week.
4. Maintain frequent contact with your veterinarian to review curves.
5. Gradually reduce the insulin dose as blood glucose levels normalize.
6. Continue monitoring closely for several months after stopping insulin to watch for relapse.

Timeline: Remission can occur in as little as 2-4 weeks or may take 3-6 months of diligent management.

Complications and Emergencies

1. Hypoglycemia (Low Blood Sugar)

Causes: Insulin overdose, missed meal, sudden increase in exercise, or improved insulin sensitivity (e.g., after weight loss).

Symptoms (Mild to Severe):

• Weakness, lethargy, wobbliness
• Disorientation, restlessness
• Twitching, seizures
• Unconsciousness, coma

Emergency Action Plan:

1. If conscious: Rub honey, corn syrup, or glucose gel on the gums. Then offer a small meal.
2. If unconscious/unresponsive: Do NOT put anything in the mouth. Contact your vet or emergency clinic immediately.
3. After stabilizing: Contact your vet for guidance on the next insulin dose. Never give insulin during a hypoglycemic episode.

2. Diabetic Ketoacidosis (DKA)

As described in the diagnosis section, DKA is a critical emergency. Treatment involves intensive hospitalization with IV fluids, short-acting insulin drip, and electrolyte correction.

3. Urinary Tract Infections (UTIs)

Diabetic cats are highly susceptible. Symptoms include straining to urinate, bloody urine, or frequent trips to the litter box. UTIs require prompt antibiotic treatment, as they can destabilize glucose control.

Living with a Diabetic Cat

Creating a Sustainable Routine

Sample Daily Schedule:

• 7:00 AM: Feed half of daily food portion → Give insulin injection → Record dose/food.
• ~12:00 PM: (Optional) Quick blood glucose check.
• 7:00 PM: Feed remaining food → Give insulin injection → Record.
• Weekly: Perform a full 12-hour glucose curve.
• Monthly: Veterinary check-in (may be remote if stable).

Travel and Care

Boarding: Choose a facility with proven experience in medical care and insulin administration. Provide written, detailed instructions and all supplies.

Pet Sitters: Invest time in thorough training. Do a practice injection session. Create a clear instruction sheet and establish a daily check-in protocol.

Quality of Life

The good news: A well-managed diabetic cat can enjoy a normal, happy, and active life. They can play, cuddle, and maintain their unique personality. The daily routine often strengthens the bond between cat and owner.

Keys to Long-Term Success:

1. Consistency in timing of food and insulin.
2. Diligent Monitoring to catch trends early.
3. Strong Partnership with your veterinary team.
4. Commitment to the process, especially in the crucial first few months.

Prognosis and Longevity

Life Expectancy

With dedicated management, the prognosis for diabetic cats is very good.

Prevention

Reducing Your Cat's Risk

Weight Management is #1: Keep your cat at a lean, ideal body condition score.

Dietary Choices:

• Feed a species-appropriate, high-protein, low-carbohydrate diet (canned food is ideal).
• Avoid free-feeding high-carb dry kibble.

Promote Activity:

• Engage in daily interactive play sessions.
• Provide environmental enrichment (cat trees, puzzle feeders, window perches).

Proactive Veterinary Care:

• Schedule annual exams for adult cats, biannual for seniors (7+).
• Include blood work as part of routine wellness checks, especially for at-risk breeds or overweight cats.

Frequently Asked Questions (2026)

Q: Can feline diabetes be cured? A: While not "cured" in the traditional sense, remission is a realistic and common goal. With early, aggressive treatment using protocols like Lantus insulin and a low-carb diet, 50-80% of cats can achieve insulin-free remission.

Q: Is giving insulin injections difficult? A: Most owners find it much easier than anticipated. Cats typically tolerate the tiny needle very well, especially when paired with a positive reward (like a bite of food). The technique is quickly mastered.

Q: What if I accidentally give a double dose of insulin? A: Contact your veterinarian or an emergency clinic immediately. Do not wait for symptoms. They will guide you on monitoring and likely advise feeding small, frequent meals and checking glucose levels often to prevent hypoglycemia.

Q: Can I use a human continuous glucose monitor (CGM) on my cat? A: Yes, devices like the Freestyle Libre are increasingly used in veterinary medicine. They provide invaluable trend data without multiple ear sticks. Always apply it under veterinary guidance, as placement and interpretation differ from human use.

Q: My diabetic cat won't eat the new prescription food. What can I do? A: Transition slowly by mixing the new food with the old. Warming the food or offering different textures (pate vs. chunks) can help. The most important factor is that the cat eats a consistent, low-carb diet—work with your vet to find an acceptable commercial option if needed.

Q: How will I know if my cat is going into remission? A: Your home glucose monitoring will show consistently normal or low-normal readings, even as you gradually reduce the insulin dose under veterinary supervision. The goal is to reach a point where the cat maintains normal sugar without any insulin.

Disclaimer: This guide is for educational purposes only and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult your veterinarian regarding your cat's health and before making any changes to their treatment plan. Never adjust insulin doses without direct veterinary guidance.

Last Updated: March 2026