DEFINITELY home test!
I feel like screaming every time I see a vet say something along the lines of 'naw, just bring kitty back every so often and we will test, do a curve and let you know how it is going.'
Excuse me? Human diabetics test their own BG 5 or 6 times a day at least, so why would my kitty be any different?
Seriously, once you get past your feelings that you are hurting your kitty, testing is easy peasy ... just go to the pharmacy and pick a meter that humans use, like Reliion or OneTouch or some other brand. Also pick up a box of lancets and test strips for whatever meter you get. Alot of people get the Relion as the test strips are cheaper I think, but it's up to you and what is available to you. While you are there, also pick up a pack of Ketostix because with high BG numbers, you want to be testing your kitty for ketones in the urine - even a trace is something to take care of immediately, so you can post online if you have any concerns on your test results.
You load a lancet into the lancet device, warm kitty's ear tip, then poke the ear along the edge with the lancet device to get a drop of blood. You have a test strip put into your meter, touch the test strip to the drop of blood which is sipped up the strip where the meter will then compute and show you a number in the window of the meter. Take a kleenex or gauze and press on the poked spot on the ear to stop the bleeding and also to lessen any chance of bruising and such.
Seriously, my 2 cats SLEEP THROUGH TESTING so there is no way it hurts. You may think it does but just poke yourself with the device. It's quick and relatively painless.
But it's VITAL to your kitty's health.
Ask your vet how much it will cost to take your kitty in for the curve. And ask your vet how it will help you one morning if your kitty has a very low BG or very high number? All that curve will do will be to show how your kitty is doing on THAT day and while STRESSED at being with the vet for a whole day.
You can inform your vet that you will be testing Spacey's BG at home where it is much more to Spacey's liking and to your pocket book. Tell your vet that you will be tracking all the BG numbers and can bring in a copy for the vet to see on your next visit.
Others have already commented on the insulins; I use Levemir for my two, but I did like Lantus as well. Starting at any higher than 1unit twice a day is too much. Do not go with a higher dose, especially if you are not home testing yet.
For foods, if you are feeding any dry foods at all, even treats, stopping those foods will contribute to better BG numbers for Spacey.
Here are some food links for you; check the Binky's list for wet low carb foods that are under 10%.
Binky’s Food Lists
Feeding Your Cat: Know The Basics of Feline Nutrition
Be sure to ask any kind of question you may have; there were always be someone around to give you a reply, even if it's just to direct you to a place or person who can answer better.
Welcome to the site.
Sorry for my rant!