Effect of lente insulin for treatment of diabetes mellitus in 12 cats.

Ultralente insulin has replaced protamine zinc insulin as the treatment of choice in treatment of diabetes mellitus in cats. There is variability in effectiveness of ultralente insulin and problems with glycemic control develop in some cats. Alternative insulin preparations are sought when ultralente insulin is ineffective. Twelve cats with insulin-dependent diabetes mellitus were treated with lente insulin. Clinical signs improved in 8 cats given lente insulin every 12 hours. Lente insulin was ineffective in 4 cats. Three of these cats were subsequently found to have an insulin resistant disorder. In 1 cat, lente insulin was ineffective because of short duration of action. Lente insulin is a viable treatment alternative when ultralente insulin is ineffective in achieving glycemic control. Ultralente insulin is still the insulin of choice for the initial treatment of diabetes in cats, because of the potential to establish glycemic control with once-a-day treatment.