CVC Highlight: Insulin therapy for diabetes mellitus in dogs and cats: Ensuring your chances of success - Veterinary Medicine
Medicine Center
DVM Veterinary Medicine Featuring Information from:


CVC Highlight: Insulin therapy for diabetes mellitus in dogs and cats: Ensuring your chances of success
Picking the right insulin product, initiating and maintaining appropriate dosing, and performing regular monitoring are key.



For newly diagnosed diabetic dogs, NPH at a starting dose of 0.5 U/kg given twice daily is recommended. Long-acting insulins such as PZI or glargine are unpredictable in dogs and not generally recommended. A bit more information is available on the use of detemir in dogs, but careful dosing is required, and the risk for developing hypoglycemia is high. Insulin mixtures should be reserved for difficult cases.


Long-acting insulin products are a suitable first choice for treatment of diabetes mellitus in cats. The starting dose for newly diagnosed patients is 0.25 to 0.5 U/kg (or 1 to 3 U/cat). A wide range of doses are used to achieve glycemic control, so start low and work up.

Studies have reported that PZI is effective (80% to 90%) in establishing glycemic control.2,3 Glargine is also effective in achieving good glycemic control in cats.4 Several studies have attempted to compare the rates of remission based on the type of insulin used, and while in small studies there has been evidence that cats treated with glargine may be more likely to achieve remission, this finding needs to be replicated in larger studies.5

Cats should be carefully monitored for the development of hypoglycemia because of the possibility of remission, and a blood glucose curve should be performed five to 14 days after any change in insulin formulation or dose.

Since intermediate-acting insulin such as Lente are generally more potent than the long-acting insulin products, they may be a better choice for patients with concurrent illnesses that can cause insulin resistance or that may make cats prone to ketosis.

Regardless of insulin formulation, twice-a-day dosing is more likely to result in good glycemic control. In addition, once-a-day dosing can increase the risk for hypoglycemia.


Always wait a minimum of seven days before increasing an insulin dose, and spot-check the blood glucose concentration in the first 24 to 48 hours after any change to detect hypoglycemia.

To evaluate a patient's response to insulin therapy, be sure consider changes in clinical signs, blood glucose curves, urine glucose concentrations, and fructosamine concentrations. Therapy changes should be based on all of these parameters. An increased blood glucose concentration may be short-lived, so it is important to look at all of the information before changing insulin dosage or formulation. Then, adjust the dose as needed and reevaluate.

Home monitoring is advisable in many cases, but some owners will go overboard with their level of blood glucose monitoring, so make sure that you are seeing those patients in the clinic from time to time and advising owners appropriately. It is also good to remember that all blood glucose meters are not the same. The ease of use and blood volume required can vary from brand to brand, so become accustomed to one type and be consistent. Another consideration is that human blood glucose meters have a built in bias at lower concentrations. They are still useful for dogs and cats, but this bias must be taken into consideration. Based on a University of California-Davis study, the most precise meters for dogs and cats are the Alpha Track (Abbott) and the One Touch Ultra (LifeScan).6

Remission in cats

Diabetes mellitus in cats can be transient or intermittent. Several studies have reported spontaneous remission of diabetes in cats after weight loss and good glycemic control was achieved.4,5 However, the rates of remission in these studies varied widely (17% to 64%). Diabetic cats that achieve remission should not be considered normal; care must be taken to watch for the return of clinical signs. The length of remission varies from one to two months to the rest of their lives. Many cats will go in and out of remission, so we should be careful in discussing the possibility of remission with owners of diabetic cats since a half to a third of cats that go into remission will relapse.4,7,8


Click here