Hi Laurie! With Lantus, you'll want to test at least three times every day--before each shot (at 6:30am/6:30pm), and then a test 6 hours into either cycle. Once a week, you'll also want to do a curve (testing every 2 hours for a 12 hour cycle).
Now, that's the
minimum you can test and safely administer Lantus. However, it's helpful if you can collect a few more tests a day, for example, get a test 4 hours in and 6 hours in. The more data you have, the more information you'll have to regulate Sampson.
Sadly, I know a lot of people end up here after having been given wrong advice from their vets because their cats aren't improving. I was fortunate enough to have a vet that recommended the same treatment as here before I found this place, but I seem to be in the minority.
Check out the Lantus Support Group:
http://www.felinediabetes.com/FDMB/viewforum.php?f=9. There's a ton of information there about Lantus that is really, really helpful. Also, if you set up a spreadsheet:
http://felinediabetes.com/FDMB/viewtopic.php?f=6&t=18207&start=0, then you can post to the board if you need advice from one of the dosing experts there. They've helped bring many cats into remission on Lantus, including my own.
You're making great choices! 80+% of newly diagnosed cats go into remission with the combination of wet food, Lantus, and regulation through home testing.