Veterinary Medicine - June 2008 - (Page c3)

What makes it work? Margie Scherk DVM, DABVP (FELINE) Cats Only Veterinary Clinic Vancouver, BC, Canada Managing diabetes mellitus in cats: While sometimes thought of as a disease entity, diabetes mellitus is a heterogeneous group of disorders in which insulin production is reduced or tissue cells are resistant to the e ects of insulin, resulting in impaired glucose homeostasis. In people, type I diabetes mellitus refers to the condition seen in individuals who are generally lean, young, and prone to ketogenesis.Type II diabetes mellitus usually occurs in older people who are often obese but less prone to the development of ketoacidosis.Type I diabetic patients require insulin therapy, whereas type II diabetics may be controlled—at least initially—with weight loss, diet, and oral hypoglycemic agents.This is because in type I diabetes, beta cell depletion results in a decreased insulin production and an absolute insulin de ciency. In type II diabetes, insulin receptor and postreceptor defects cause impaired insulin uptake by tissues.This insulin resistance and associated hyperglycemia cause the beta cells to produce more insulin; thus, this state is one of a relative insulin de ciency at the tissue level.Various levels of absolute or relative insulin de ciency exist (see Table 1, page 5). In cats, the categorization of diabetes is not as clear. Generally, diabetes is a disorder of older, often overweight cats that are not prone to ketogenesis, more similar in signalment to type II diabetes in people. However, obese cats appear to have a defect in insulin secretion along with lower tissue sensitivity to insulin.1,2 Weight loss of even 10% to 15% results in improved tissue sensitivity, but, often by the time of diagnosis, these cats require treatment with insulin. Cats may also develop diabetes secondary to primary pancreatic disease, endocrinopathies (e.g., acromegaly, hyperadrenocorticism), or drug therapy (e.g., glucocorticoids, progestins). Risk factors for feline diabetes include weighing greater than 7 kg (15.4 lbs), not being physically active, or being over 9 years old, a neutered male, or a Burmese.1,3 Complications of unregulated diabetes mellitus In short, diabetes mellitus results in cell starvation in the presence of hyperglycemia.While cell starvation results in polyphagia with concurrent weight loss, hyperglycemia results in polyuria and compensatory polydipsia due to glucose spilling into the urine and osmotically drawing water with it. Some diabetic cats are a ected by a polyneuropathy that can result in functional, structural, and biochemical defects in the peripheral motor and sensory nerves of the limbs. It generally a ects the pelvic limbs more than the thoracic limbs.4 The pathology in nerve biopsies from 12 cats with spontaneously occurring diabetes included damage to Schwann cells, demyelination of nerve bers, thin myelin sheaths, and an overall decrease in myelinated ber density.5 See Table 2 (page 6) for a list of functional changes associated with unregulated feline diabetes. Di erent than in people, diabetes does not 3

Table of Contents Feed for the Digital Edition of Veterinary Medicine - June 2008

Veterinary Medicine - June 2008 Contents Leading Off Clinical Exposures Idea Exchange A Challenging Case: Conjunctival Lymphoma in a Cat Updates on Canine Hypoadrenocorticism Product Preview CE Form Advertiser Index Marketplace/Classifieds Mind Over Miller Clinical Edge - June 2008 Table of Contents Managing Diabetes Mellitus in Cats: What Makes it Work? Porcine Insulin Zinc Suspension in the Management of Feline Diabetes Mellitus Monitoring Diabetes Mellitus in Diabetic Cats Feline Diabetes Mellitus: Important Client Communication Points

Veterinary Medicine - June 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.