Will Falconer, DVM Moderator
No outward signs? I suspect he's minimally more thirsty and urinating more than usual, as both his blood glucose and urine glucose are way out of normal range.
Raw food with low or no starch would be best. Diabetes is a carb disease, and it takes carbs to make kibble stick together.
Just be aware that kibble has been recalled repeatedly for salmonella. It just doesn't make the news. Use good hygiene around the raw food and have your husband exercise caution on handling the dogs (mouths and anus and stools to be avoided).
All the best with the challenges before you.