Feline Diabetes Mellitus
A common endocrine disorder where the body cannot properly regulate blood sugar. Most cats have Type 2-like diabetes associated with obesity. With proper management, many cats achieve diabetic remission.
Last updated: 2026-05-09
Severity
moderate
When to Act
See Vet Soon
Symptoms & Signs
Increased thirst and urination
Water bowl empties quickly; litter box clumps are larger and more frequent.
Weight loss despite good appetite
Cat eats normally or excessively but loses body mass.
Increased appetite or anorexia
Early stage: ravenous. Late/uncontrolled: complete appetite loss (a dangerous sign).
Plantigrade stance
Walking on hocks (heels) instead of toes — indicates diabetic neuropathy.
Lethargy
Cat sleeps more and seems less interested in activity.
Poor coat quality
Dull, dry, flaky coat from metabolic derangement.
Behavioral Changes to Watch For
Pets can't tell us what's wrong. These behavioral changes are often the first clues that something is wrong.
🐾 Litter box changes
Much larger and more frequent urine clumps; may start having accidents outside the box.
What You May Notice:
You're scooping significantly more urine and changing litter more frequently than before.
🐾 Weakness in hind legs
Diabetic neuropathy causes hindlimb weakness, leading to a flat-footed walk.
What You May Notice:
Your cat walks on their hocks instead of their toes and may have trouble jumping.
Causes & Risk Factors
Causes
- •Insulin resistance (most common — obesity is primary driver)
- •Beta-cell dysfunction/reduced insulin production
- •Chronic pancreatitis damaging pancreatic islet cells
- •Insulin-antagonistic conditions: hyperthyroidism, Cushing's, acromegaly
- •Drug-induced (corticosteroids, progestins)
Risk Factors
- ⚠Obesity — single biggest risk factor
- ⚠Age: middle-aged to older cats (8-13 years)
- ⚠Male cats (slightly higher risk)
- ⚠Burmese cats (genetic predisposition)
- ⚠Physical inactivity and indoor-only lifestyle
- ⚠High-carbohydrate dry food diet
How It's Diagnosed
- 1Persistent fasting hyperglycemia (>250-300 mg/dL)
- 2Fructosamine — reflects average blood glucose over past 2-3 weeks
- 3Urinalysis: glucosuria (glucose in urine)
- 4Rule out stress hyperglycemia (common in vet visits)
- 5Screen for concurrent diseases: pancreatitis, hyperthyroidism, UTI
Treatment Options
Low-Carbohydrate Diet
Dietary therapy is the cornerstone — some cats achieve remission on diet alone.
Steps
- 1.Feed canned/pouch high-protein, low-carbohydrate diet (<10% calories from carbs)
- 2.Examples: Fancy Feast Classic pâté, Purina DM, or similar veterinary diets
- 3.Ideally feed as meals (not free-fed) to better match insulin therapy
- 4.Weight loss in obese cats — slow and steady (0.5-1% body weight per week)
Expected Outcome
Up to 30-40% of newly diagnosed cats achieve remission with diet change alone.
Precautions
- !Rapid weight loss is dangerous in cats — must be gradual
Insulin Therapy
When diet alone is insufficient, insulin is the first-line medication.
Steps
- 1.Glargine (Lantus) or PZI insulin — both excellent for cats
- 2.Typically 1-2 units twice daily, 12 hours apart
- 3.Administered with U-100 insulin syringes (0.3 mL with half-unit markings)
- 4.Home blood glucose monitoring (ear prick) or Freestyle Libre continuous monitor
- 5.Dose adjusted based on blood glucose curves
Expected Outcome
Good glycemic control in most cats; potential for remission with tight regulation.
Precautions
- !Insulin overdose can cause life-threatening hypoglycemia
- !Always confirm the cat is eating BEFORE giving insulin
- !Keep corn syrup at home for hypoglycemia emergencies
- !Insulin type and syringes must match (U-40 vs U-100)
Oral SGLT2 Inhibitors (Newer Option)
Bexagliflozin (Bexacat) or Velagliflozin — oral, once-daily tablets that excrete glucose through urine.
Steps
- 1.Only for cats without prior insulin therapy and without ketosis risk
- 2.Once daily oral tablet — no injections needed
- 3.Cat must be closely monitored for ketoacidosis risk
Expected Outcome
Good glycemic control in appropriate candidates.
Precautions
- !Risk of euglycemic diabetic ketoacidosis (EDKA) — a potentially fatal complication
- !Only for cats that are good candidates (no history of DKA, not on insulin)
- !Requires careful screening and monitoring
Common Medications Used
| Medication | Usage | Important Notes |
|---|---|---|
| Glargine (Lantus) | Long-acting insulin — first choice for feline diabetes | Twice daily dosing. Associated with the highest remission rates when combined with a low-carb diet. |
| Bexagliflozin (Bexacat) | SGLT2 inhibitor — oral alternative to insulin | Only for select newly-diagnosed cats. Contraindicated in cats with prior insulin use or DKA history. |
Prevention
- ✓Maintain ideal body weight — obesity is the #1 risk factor
- ✓Feed a high-protein, low-carbohydrate diet
- ✓Encourage daily exercise through play and environmental enrichment
- ✓Routine senior blood work for early detection
When to See a Veterinarian
- ⚠️First signs: increased thirst/urination + weight loss
- ⚠️Cat stops eating — this is an emergency (risk of hepatic lipidosis and DKA)
- ⚠️Signs of hypoglycemia: weakness, disorientation, seizures, coma
- ⚠️Sweet/fruity breath odor — may indicate ketoacidosis
Frequently Asked Questions
Can diabetes in cats be reversed?
Prognosis
Good to excellent with proper management. Up to 50-80% of cats achieve diabetic remission (no longer need insulin) with early aggressive management, especially with glargine + low-carb diet. Remission can be permanent or may relapse.
References
- [1] AAFP — Diabetes Management Guidelines
- [2] ISFM — Feline Diabetes Consensus
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