The reason we recommend the Relion brand meters from WalMart is because the price of testing strips on the other meters is pretty darn ridiculous, so you might check to see how much they are for the meter they give you. The Confirm and Micro meters also take the tiniest blood sample...and when you're poking new ears, that's really helpful!
How much does Snuggy weigh? Lantus has a starting formula and 2 units is a really high starting dose. Most of the cats here start on .5 to 1 unit every 12 hours. There are also 2 protocols here for Lantus. The
Tight Regulation Protocol offers the best chance of remission, but the
Start Low, Go Slow method works better for some people.
Most cats will act like they're starving if the BG goes too low...that's how I can always tell I need to get an extra test in on China...she will NOT leave me alone wanting food. The problem with "waiting to see symptoms" is that a lot of times, there are no symptoms of low blood sugar until they start to have seizures, which is why home testing is so important, as well as learning how your cat responds to both food and insulin.
Depending on which protocol you choose, when they drop below a certain number (50 for Tight Regulation and 90 for Start Low, Go Slow) you should have some high carb foods in the house and give a teaspoon at a time until they're up into safer numbers. The "gravy" part of the Fancy Feast Gravy Lovers foods has the most carbs in it, and by just feeding the gravy part, you don't risk filling the cat up in case you need them to eat again later. If using honey, Karo or syrup, a couple of drops is usually enough to bring them up, but it wears off quickly
As for "when do I go to the vet", I can only say that the vast majority of the people here never get to that point when it comes to hypo situations because we do test often and know what to do if they start to go too low, but here's a page you should probably print out and keep somewhere safe titled
"How to treat HYPO'S...they can kill" that also describes the different stages of hypoglycemia. Of course if there's any doubt, the safest thing is to get to the vet!
You might take him back with you to the shelter and ask that they shave a small patch for you to use to shoot in to....it's much easier, especially with a long haired cat to have that shaved spot ...at least until you learn the "feel" of it....and as the hair grows back in, you'll learn how to deal with it
When you start testing, it'll really help to use our spreadsheet to keep track of his numbers too. Here's
"How to create a spreadsheet" instructions. The spreadsheet is every bit as valuable a tool as low carb food, testing and a good insulin!