Diabetes Mellitus is the scientific term to describe partial or complete lack of insulin, resulting in alteration of blood glucose.

Canine diabetes is similar to Type 1 diabetes in people. It results from an inability to produce insulin, most commonly related to immune-mediated destruction of the pancreas. Canine diabetics usually require lifelong insulin treatment.

Feline diabetes resembles Type 2 diabetes in people. A combination of insulin therapy, dietary management, and lifestyle changes are utilized to manage feline diabetes and can result in remission of signs, though often temporary.^[1] Most insulin types used in cats have been associated with remission^[1],^[2].

Several insulin types are commercially available for diabetes maintenance. As with people, there isn’t an insulin product that is effective in managing every patient and individual response to insulin therapy can be unpredictable.

Insulin FDA-approved for dogs and cats

Porcine Lente Insulin: An intermediate-acting insulin and is a 40 IU/ml concentration.^[3],[4] The product was first launched in the United States under the brand name, Vetsulin® in 2004. In Canada and other countries, it is sold under the brand name Caninsulin®. The labeled starting dose of Vetsulin is 0.5 IU/kg given once daily.^[3] 

Approximately one-third of canine patients can be regulated on single daily doses. The initial recommended dose of Vetsulin in cats is 1-2 units/cat twice daily.^[3] Vetsulin is a veterinary prescription product sold through the veterinary channel.

Insulin FDA-approved for cats

Protamine Zinc Insulin (PZI): A long-acting insulin sold under the brand ProZinc®. PZI insulin is a 40 IU/ml insulin used at a starting dose of 0.2-0.7 IU/kg SC every 12 hours for cats.^[4],[5] ProZinc® is a veterinary prescription product sold through the veterinary channel.

Human insulins: extra-label use

Neutral Protamine Hagedorn (NPH): An intermediate-acting insulin sold under the brands, Novolin® N or Humulin® N. NPH is a U100 insulin manufactured for human diabetes management, but is used off-label in dogs. The starting dose is 0.3 to 0.4 U/kg twice daily in dogs.^[4]  The duration of action in cats is often insufficient, so its use is not typically recommended. NPH is available through most human pharmacies.

Insulin Detemir: A long acting insulin sold under the brand Levemir®. It is a 100 IU/ml insulin manufactured for human diabetes management. The starting dose of detemir in dogs is 0.1 to 0.2 Units/kg SC q12h^[4]. Canine insulin receptors appear to be 4X more sensitive than human receptors to detemir and, therefore, may be hard to dose in small dogs.^[1],[6] Detemir is available through most human pharmacies.

Human insulin used extra-label in cats

Insulin Glargine: A long-acting insulin sold under the brand Lantus®. It is 100 IU/ml insulin manufactured for human diabetes management, but is often used extra-label in cats.

According to Plumb’s Veterinary Formulary, 0.25 Units/kg of ideal body weight SC q12h should be given to cats with blood glucose levels < 360 mg/dL and 0.5 Units/kg of ideal body weight SC q12h in cats with blood glucose levels > 360 mg/dl^[4]. Glargine is available through most human pharmacies.

Author Bio:  Nyssa Reine-Salz, DVM, is a graduate of the University of Florida, College of Veterinary Medicine. She completed an internship in Small Animal Internal Medicine and Surgery and a residency in Small Animal Internal Medicine at the AMC in New York, N.Y. After achieving Board Certification in Internal Medicine, Dr. Reine-Salz was on staff at the Animal Medical Center with a focus on nephrology and endocrinology until 2009. Reine-Salz has worked for Merck Animal Health as an Internal Medicine Consultant with an emphasis on diabetic support since 2012.

Copyright (C) 2016 Intervet Inc., doing business as Merck Animal Health, a subsidiary of Merck & Co., Inc. All rights reserved.

This content was provided by Merck Animal Health.