Caninsulin® Cartridges for VetPen (2.7 mL, 40 IU/mL)

What Caninsulin® Is and How It Works

Caninsulin is a porcine insulin zinc suspension (lente), U-40 strength, used to manage diabetes mellitus in dogs and cats. These 2.7 mL cartridges are designed for the VetPen delivery device and help provide accurate, repeatable dosing. Many pet owners look for Caninsulin Cartridges for VetPen to simplify daily injections, including those searching for caninsulin cartridges without insurance options.

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Caninsulin lowers blood glucose by replacing deficient endogenous insulin, promoting uptake of glucose into tissues and reducing hepatic glucose output. It has an intermediate duration of action in dogs and cats, with twice-daily dosing commonly used after stabilization.

Dosage and Usage

• Species and route: For dogs and cats, subcutaneous use only as directed by a veterinarian.
• Starting doses: Dogs are often started around 0.5 IU/kg twice daily. Cats are commonly started at 1–2 IU per injection twice daily. Individual plans vary.
• Titration: Doses are adjusted based on clinical signs and glucose monitoring or curves. Changes should be gradual.
• Administration cadence: Many patients receive twice-daily dosing about 12 hours apart.
• Injection sites: Rotate sites along the lateral thorax or abdomen to reduce irritation.
• Cartridge mixing: Before each use, gently invert the VetPen with the cartridge 10–20 times until the suspension appears uniformly milky. Do not shake vigorously.
• Prime the pen: Attach a new pen needle. Dial a small test amount and prime until a drop appears at the tip, per device instructions.
• Dial and inject: Dial the prescribed dose, insert subcutaneously, depress the button fully, and hold for 5–10 seconds to ensure delivery. Confirm the dose window has returned to zero.
• Missed dose: Do not double the next dose. Resume the regular schedule and contact the prescribing veterinarian for guidance.
• Device care: Use a new sterile needle for each injection. Replace cartridges when empty or when beyond in-use time.

• Unopened storage: Keep unopened cartridges refrigerated at 2–8°C (36–46°F). Do not freeze. Protect from light.
• In-use storage: Follow label guidance. In many markets, an in-use cartridge may be kept below 25°C (77°F) away from heat and light for a defined period; otherwise refrigerate. Always check the local product insert.
• Handling: Do not expose to freezing or excessive heat. Discard if frozen, discolored, or if clumps do not disperse when gently mixed.
• Travel: Use an insulated cooler pack to keep cartridges within the correct temperature range. Keep the pen and needles with you during flights; do not place in checked luggage.
• Expiration: Observe the in-use discard date specified in the product insert for cartridges once punctured.

Benefits and Savings

Caninsulin supports stable glycemic control, which can help reduce polyuria, polydipsia, and weight loss in diabetic dogs and cats. VetPen cartridges add convenience, reduce dosing steps, and can increase accuracy compared with drawing doses from a vial.

The cartridge format may lessen dose variability and simplify daily routines for families administering long-term therapy. Many customers save 60–80% vs typical U.S. prices. Options are available for those purchasing caninsulin cartridges without insurance.

See our promotions page for current offers, including any caninsulin cartridges coupon if available.

Side Effects and Safety

• Common effects: Mild lethargy, increased or decreased appetite around dose changes, and transient injection site reactions (small lumps, redness).
• Hypoglycemia signs: Weakness, trembling, ataxia, confusion, hunger, disorientation, seizures in severe cases. This risk increases if food intake is reduced or other glucose-lowering drugs are used.
• Hyperglycemia signs: Excess thirst and urination, weight loss, lethargy. May indicate the need for reassessment.
• Gastrointestinal: Occasional vomiting or diarrhea may occur during dose adjustments.
• Injection technique issues: Pain on injection or inconsistent control may signal technique or resuspension problems.

Serious risks include severe hypoglycemia and diabetic ketoacidosis if undertreated or during intercurrent illness. Use caution in animals with concurrent endocrine disease, severe kidney or liver disease, or during pregnancy and lactation. Corticosteroids, progestins, thyroid medications, and certain diuretics can alter insulin requirements. When used with insulin secretagogues, the hypoglycemia risk may rise; veterinary guidance is essential.

Onset Time

Clinical signs such as excessive thirst and urination often improve within days as doses stabilize. In dogs, intermediate action typically supports twice-daily dosing, with meaningful glycemic improvements over 1–3 weeks. Cats may require several weeks for full dose optimization, and periodic curves help refine dosing.

Weight and coat condition can improve over several weeks to months when glycemic control is sustained. Individual responses vary with diet, concurrent conditions, and adherence to the dosing schedule.

Compare With Alternatives

ProZinc® (protamine zinc insulin, U-40) is another veterinary insulin often used in cats and some dogs. It has a different duration profile than lente insulin. Some clinicians choose it for feline patients who need longer coverage.

Insulin glargine (Lantus®, U-100) is frequently used in cats and may support remission in select cases under close monitoring. Its longer, smoother profile differs from lente insulins, and syringes or pens calibrated for U-100 are required if used.

Insulin detemir (Levemir®, U-100) is another long-acting option sometimes used in cats and large dogs. Potency and dose scaling differ from other insulins, so careful veterinary guidance is needed when switching.

Compared with vials, VetPen cartridges can reduce handling steps and make daily administration more consistent. Choice among these options depends on species, response, and veterinary treatment goals.

Combination Therapy

• Insulin plus nutrition: Veterinary-prescribed diet changes (including consistent timing and composition) are foundational with any insulin therapy.
• Insulin plus monitoring: Home glucose monitoring or periodic glucose curves guide safe titration and help identify hypoglycemia risk.
• Concurrent meds: Drugs that lower glucose may require dose reductions to reduce hypoglycemia risk. Medications that raise glucose may prompt insulin adjustments.
• Lifestyle: Consistent feeding schedules and activity patterns support stable insulin action and fewer swings.

Patient Suitability and Cost-Saving Tips

Caninsulin is indicated for dogs and cats diagnosed with diabetes mellitus. It is not for use during episodes of hypoglycemia or in animals with known hypersensitivity to pork-derived insulin. Caution is advised with severe systemic illness, pregnancy, or lactation; the veterinarian will assess risks and benefits.

To manage costs, consider ordering multiple cartridges in one shipment and planning ahead so therapy is not interrupted. Reorder reminders can help maintain continuity. Using the VetPen may reduce wasted doses compared with drawing from a vial, and proper storage prevents spoilage.

When switching insulins or delivery devices, veterinary supervision is required to set the new starting dose and reduce hypoglycemia risk. Syringe calibration must match insulin strength (U-40 for Caninsulin; U-100 for certain alternatives) if syringes are used.

Authoritative Sources

Manufacturer information for Vetsulin VetPen and cartridges (Merck Animal Health)

Caninsulin on the Health Canada Drug Product Database

FDA page for Vetsulin (product information and resources)

Order Caninsulin from CanadianInsulin: add to cart, upload your prescription, and we ship with prompt, express, cold-chain handling.

This page is educational and does not replace professional medical or veterinary advice. Always consult a licensed veterinarian for diagnosis and treatment decisions.