Diabetes Mellitus

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Diabetes mellitus

• Chronic disease caused by deficiency of insulin and therefore disorders of carbohydrate metabolism
• Occurs in most species, most commonly in dog and cat

Aetiology

Can be caused by

• Absolute deficiency of insulin
• Antagonism of insulin by hormones from the adrenal and thyroid glands, anterior pituitary causing high levels of blood glucose
• Complication of pancreatic fibrosis
• Insulin binding antibodies, insulinase and plasma antagonists imbalance

Clinical signs

• Hyperglycaemia
• Polyuria
• Polydypsia
• Ketonuria
• Metabolic acidosis
• Reduced cardiac output (due to loss of water and sodium), reduced blood pressure and renal flow causing circulatory collapse, coma and death

Pathology

• Pancreas appers normal or reduced in size due to fibrosis
• In cats, amyloidosis is sometimes present in the islets
• Fatty change is consistently present in the liver and kidneys
• The lens in the eye is often opaque due to deposition of sorbitol causing it to swell (glucose is converted into sorbitol once the glycolytic pathway is saturated)