Over the past six years we have tried several different types of insulin: Humulin NPH, Humulin Lente, Humulin Ultralente, Lantus, BCP PZI, and PZI Vet. Of the Humulins, Lente worked the best but as of three years ago it is no longer available. I then tried PZI Vet with her and it worked even better than the Lente did, but it was recently discontinued as well. It seems that every time we find an insulin that works for her it is taken off the market within a few years, which is very frustrating. Chu has been a low-carb kitty since 2002; she eats a canned-only diet of Fancy Feast (the ones made without grains, gluten and "gravy") because her blood glucose levels are much more controlled without carbs in her system. She eats two cans per day and is not allowed any dry food or high-carb snacks