Bandit has eaten 4 meals a day (every 6 hours) since he was diagnosed with diabetes in 2009. He went into remission in 2010, and he was in remission for 5 years eating low carb, canned food 4 times a day. Cats' metabolisms are twice as fast as people's or dogs', so it is actually best for for cats to eat smaller meals, 4 times a day, and it helps level out their blood sugar which contributes towards good regulation. The Fancy Feast Fish & Shrimp flaked is low carb so it is fine for him to eat for now, but you might want to try out some other foods just because it is a bit high in phosphorus for a senior cat. If he seems to like shredded, chunkier foods, maybe you can try out some
Tiki cat, some BFF (Best Feline Friend), or some
Weruva? There are lots of good shredded fish, non-fish, and combination flavors of both, and most a bit better in the phosphorus department. The BFF is especially good at enticing picky cats! (I linked to store locators for the foods above).
Honestly, I would look for a different vet. I'm in upstate NY so unfortunately I can't recommend a vet in the city, but I am hoping someone here can! Here is why I think you should change vets. First, the vet is not following the current
treatment recommendations for diabetes in cats in several ways--home testing should be strongly encouraged (and a human meter is just fine). Second, Humulin is not a good insulin for cats, and most cats do not do so well on it because it just doesn't last long enough to provided good control over blood sugar levels (the recommended insulins for cats are Lantus, Levemir, and Prozinc). Third, it seems like your vet already has a "my way or the highway" attitude when it comes to the feeding time, which doesn't make it likely she'll be receptive to you wanting to change the treatment she is recommending. You definitely need a vet that is a bit more up to date in their treatment recommendations, and is willing to work with you.
So now for some tips! You can pick up a human meter at the drug store and learn to test at any time--you do not need your vet's permission and it will save you the money you're spending getting the testing done there. Adjusting the dose based off numbers you've gotten at the vet's office is dangerous--most cats will have inflated blood sugar numbers because of stress. Many people here use the Relion meters from Walmart because the test strips are cheap (and having low cost test strips is very important because you'll need to test several times a day). Here are some links to help you get started with the testing:
http://www.felinediabetes.com/FDMB/threads/hometesting-links-and-tips.287/.
In regards to insulin--I can't speak to the price of Prozinc or Levemir because Bandit has always been on Lantus, but the initial cost of Lantus is more expensive than Humulin up front. However, with a little smart buying, you can get the costs down to where you can certainly afford it (especially if you start saving yourself money at the vet by home testing)! Bandit had to go back on Lantus this month because he was diagnosed with an immune disorder and had to start taking steroids, which knocked him out of remission. I just about died from sticker shock when I found out how much the price of Lantus has gone up in the past 5 years! Luckily, the wonderful people here directed me to
Mark's Marine Pharmacy, where you can buy insulin online from Canada. The most economical way to buy Lantus is to have your vet write you a script for the Lantus
pens (5 pack), and then draw the insulin out of the pens with a syringe just like you would a vial. Including shipping to NY, the total cost of the pens was $158, and handled properly, they will last me at least 10 months, if not more. So if you're spending $30+ dollars on the Humulin per month, ordering the Lantus this way is cheaper, AND it is less dangerous and will work far better for your cat.
Best of luck, and I hope someone will stop by with a new vet recommendation for you!