Complications of Canine diabetes

The long-term complications of diabetes are a result of prolonged high blood glucose (hyperglycaemia).

Due to their shorter life span, diabetic dogs seem to develop fewer long-term complications than human diabetics. Obtaining optimal control of blood glucose helps to minimise the long-term complications of diabetes mellitus.

Diabetic cataracts

This is the most common complication of canine diabetes.

A cataract is when the lens of the eye becomes opaque, blindness results in the affected eye or eyes. Cataracts in dogs with diabetes are seen far more often than in cats with diabetes.

What causes diabetic cataracts?

High blood glucose levels (hyperglycaemia) causes changes in the lens of the eye. Water diffuses into the lens causing swelling and disruption of the lens structure. This results in the opacity that is seen.


If a cataract is present the lens of the eye can be removed surgically to restore vision. Control of high blood glucose concentrations should help prevent or delay the onset of diabetic cataracts.