Memphis, who is now diabetic (hopefully temporarily), started eating clay litter a few years ago. After a battery of tests to rule out this and that to account for his severe anemia, the vet decided he had immune mediated hemolytic anemia. Sometimes there is no obvious cause, but sometimes it results after vaccinations and the immune system goes into overdrive and attacks the red blood cells. We put him on prednisolone, and no further vaccinations. He was fine until we had to change to dexamethasone (pred is periodically unavailable), and up his dosage for what maybe was an erroneous drop in red cell count. The upped dosage of steroid triggered the rise in blood sugar. We are trying to reduce his steroid (and maybe get him off of it), make sure he eats a low carb canned diet, and hope his sugar goes back to normal.