I like the idea of everyone getting their own container and not needing seperated because they are all getting the same thing then.
Lots of us here feed Fancy Feast (the Classic pate formulas, for example are very low-carb, among some others) & certainly if they're all eating the same low-carb food, will be both easier on you and healthy for all of your cats!
So is your newly-diagnosed Juliet on insulin now, or is the vet having you try low-carb diet control first?
As you said you'd rather not have to separate your 4 kitties at mealtimes, a word of caution: A diabetic cat also needs
portion control - even on a low-carb diet - so that Juliet is eating the proper amount of food every day for her
ideal body weight. (Is she underweight? Overweight? You didn't say.) Unless you can make certain that Juliet will
not be getting into the others' meals in addition to her own, you may want to separate her from the others
and make certain your others have finished eating before allowing her to rejoin her buddies. Because when a diabetic kitty eats more than she should (some are pretty sneaky about that, too), it will make it that much harder for you to get her blood glucose regulated and back within normal limits.
Wishing you the best of luck with Juliet!
