My dog Katie, who passed away 3 years ago, was diabetic for several of her last years. We did buy her some of the 'special' Science Diet food, but more often we basically prepared well-balanced meals for her, lower on carbs. We checked her blood sugar with a regular meter - found the best place to take her blood was on her elbow callus.

Yep, my dog RIP Timber had diabetes for 7 of her 14 years. It is manageable, special diet, shots 2xs/day, blood curves at vet to check dosage requirements. Blindness is common due to glaucoma but they do quite well blind as smell is a huge asset. Weakness in legs occasionally, if blood levels are good=no accidents/peeing.