On various pet health websites, and also in the veterinary hospital I work in, I've seen questions and debates about whether or not dry cat food causes diabetes in cats. To me this question is missing the point a bit.
Just like in people, there isn't necessarily any one or few things that cause diabetes. There are risk factors. Having a lot of risk factors increases your risk of developing diabetes, but doesn't mean that you will. Cats are the same. Dry food may be a risk factor, but plenty of cats live happily their whole life eating dry cat kibble. If they don't have any other risk factors to developing diabetes, then dry cat food alone probably isn't enough to push them over the edge.
The important question, in my mind, is how to best help cats who are diabetic right now. If we could predict these kinds of things beforehand, that would be wonderful, but we can't. Even with every risk factor to diabetes development present, many cats will remain healthy. Living bodies are still mysterious that way.
So without further delay, here's all the information I tracked down in my research about why diabetic cats should eat canned cat food:
Why Diabetic Cats Should Only Be Fed Canned Cat Food
