About a week ago I found out Bob has diabetes. He has been at the water bowl constantly, eating a ton, losing weight and filling the litterbox a LOT. I took him in to get his blood and urine tested, and sure enough, he's got it. He has to go on special food and insulin called Glargine twice a day. The good thing about all this, possibly, is that he may go into remission after about 2 months with this new insulin.
I hope it works! He seems to already be drinking and urinating less, so that's a good sign!