I think Adara had a dobe with water diabetes?
"Water" diabetes is diabetes insipidus and a whole different disease than diabetes mellitus (what people are usually talking about when they talk about "diabetes".
We see a ton of diabetic cats in the clinic where I work. We also see a few diabetic dogs--most are smallish breeds--min pins, lhasas, ocassional toy or miniature poodles. But I've had Dobes since 1959 and can't think of any Doberman owned by people I've known that had diabetes.
I do know of a couple of Dobes who were actually diagnosed with diabetes insipidus. It's often hard to get a confirmed dx for di because the only way to dx it is to rule out everything else--not easy to do. One of the Dobes that was diagnosed with diabetes insipidus was seen by a specialist--who finally said that the di was secondary to a form of lupus the dog had.
But I sure wouldn't put Dobes in any sort of a high risk category for the common variety of diabetes (but who knows if that's what they were talking about?)