The treatment of canine and feline diabetes using insulin

Veterinary insulin is specifically formulated for the treatment of diabetes mellitus in dogs and cats.

Types of insulin and insulin analogs

The source of insulin used in insulin preparations can vary. Some preparations contain porcine insulin. Recombinant human insulins are also available. Insulin analogs (or insulin receptor ligands) are synthetic analogs of insulin created by genetic engineering which perform the same actions as insulin in the body.

Insulin preparations can be divided into three categories:

1. Long-acting insulins and insulin analogs
   • Ultralente insulins - 100% crystalline insulin
   • PZI insulins - contain protamine and zinc
   • Insulin glargine and insulin detemir are insulin analogs that are released slowly over a period of up to 24 hours (in humans) and intended to supply a basal level of insulin.
2. Intermediate-acting insulins
   • Lente insulins - mixtures of 30% amorphous (semilente) and 70% crystalline (ultralente) insulin in an aqueous suspension.
   • NPH insulins - contain protamine
3. Rapid-acting insulins and insulin analogs
   • Soluble insulin and semilente insulin: intravenous administration possible
   • Insulin lispro, insulin aspart and insulin glulisine are insulin analogs that readily absorbed from the injection site which are used to provide a bolus of insulin for after a meal (in humans)

Due to differences in metabolism, the duration of activity of any particular insulin will vary from animal to animal.

Insulin formulated for veterinary use has a strength of 40 IU/ml meaning small dose volumes can be measured fairly easily and accurately. Human insulin preparations have a strength of 100 IU/ml. Special 40 IU/ml syringes are available for accurate measurement of insulin doses. Insulin is available in 2.5 ml or 10 ml vials taking all sizes of pets into consideration.

Porcine insulin zinc suspension - Intermediate acting insulin for the treatment of diabetes in dogs and cats

Porcine insulin is identical in structure to canine insulin and similar in structure to feline insulin.

Twice daily injections with porcine insulin zinc suspension has been proven to be effective for the control of diabetes in cats.¹

Twice daily and in some cases once daily injections with porcine insulin zinc suspension is effective for the control of diabetes in dogs.^{2, 3}

¹Martin GJ, Rand JS. Control of diabetes mellitus in cats with porcine insulin zinc suspension. Vet Rec. 2007;161(3):88−94

²Horn B and Mitten RW (2000) Evaluation of an insulin zinc suspension for control of naturally occurring diabetes mellitus in dogs. Australian Veterinary Journal 78(12):831-4.

³Monroe WE, Laxton DJ, Fallin EA and others(2005) Efficacy and Safety of a Purified Porcine Insulin Zinc Suspension for Managing Diabetes Mellitus in Dogs. J Vet Intern Med 19:675-682.