Dog Diabetes: Insulin Types (NPH, Lente, Glargine), Glucose Curves, Complications (Cataracts, Neuropathy)

Dog Diabetes Insulin Types

Canine diabetes mellitus affects 1 in 300 dogs, requiring lifelong insulin twice daily, consistent low-carb diets, and glucose curve monitoring to prevent life-threatening hypoglycemia or hyperglycemia. NPH or lente insulin starts at 0.25–0.5 U/kg q12h, with glargine (0.25–0.5 U/kg q12h) for short-duration cases; complications include cataracts (75% develop within 6 months), peripheral neuropathy, and dental disease worsening glycemic control. This comprehensive guide examines diabetes management across USA, UK, Australia, and Asian markets, analyzing insulin selection/dosing, at-home glucose curves (every 2-4h x12h), continuous glucose monitors (CGM), cataract surgery considerations, and dental disease link requiring prophylaxis.

Insulin Types and Dosing Protocols

NPH (Neutral Protamine Hagedorn): Intermediate-acting human insulin, first-line starting 0.25–0.5 U/kg q12h SC. Duration 8-12h dogs; nadir 4-8h post-injection. Cost-effective ($20-40/vial).

Lente (Porcine Zinc Insulin): Veterinary intermediate insulin, 0.25–0.5 U/kg q12h; duration 10-14h. Vetsulin discontinued 2017, generics available.

Glargine U100: Long-acting for short NPH/lente duration, 0.25–0.5 U/kg q12h; median dose 0.5-0.6 U/kg. Lantus human formulation works ($80-120/vial).

Detemir: Not recommended dogs (short duration).

Dosing Rules: Start conservative (0.25 U/kg small breeds, 0.5 U/kg large); increase 10-25% based on curves; never exceed 1.5 U/kg without specialist consult.

Glucose Curve Monitoring

Traditional Curve: BG every 2h x12h starting pre-insulin, documenting nadir (lowest BG 4-8h post), peak postprandial (2h meal), and pre-next dose (>150 mg/dL ideal). Home curves preferred avoiding stress hyperglycemia.

Targets: Pre-insulin 150-300 mg/dL, nadir >80 mg/dL, no hypoglycemia.

Continuous Glucose Monitors (CGM): Freestyle Libre sensors (14-day wear) eliminate fingersticks, alerting hypoglycemia/hyperglycemia. Veterinary validation confirms accuracy; $100-150/sensor.​

Complications: Cataracts, Neuropathy, Dental Disease

Cataracts: 75% diabetics develop bilateral cataracts <6 months diagnosis due to sorbitol accumulation lens fibers. Surgery success 90-95% with controlled DM (phacoemulsification $3,000-5,000). Pre-op: strict BG control (<200 mg/dL), topical NSAIDs uveitis prevention.

Neuropathy: Peripheral neuropathy (Horner’s syndrome 12%, NKCS) 20x nondiabetics; resolves glycemic control.​

Dental Disease: Periodontitis worsens insulin resistance; annual prophylaxis essential.​

Diet and Lifestyle Management

Consistent Low-Carb Diets: 12% max carbohydrate prescription (Hill’s w/d, Purina DM); feed BID matching insulin.

Exercise: Consistent daily walks; avoid variable activity affecting requirements.​

International Protocols

USA/UK/Australia: AAHA/IDEXX guidelines standardize NPH/glargine, CGM adoption growing.
Asia: Insulin access variable; human NPH common.​

Common Questions

Starting insulin dose? 0.25-0.5 U/kg q12h.
Glucose curve frequency? Monthly first 3 months, quarterly stable.
Cataract surgery timing? BG <200 mg/dL stable.​
Hypoglycemia signs? Weakness, ataxia, seizures—immediate honey/corn syrup.​

Consistent insulin, curves, dental care, and cataract management enable good quality life.