. I am bringing him in so they can watch and see how insulin is doing in about 3 weeks.
I am going to buy machine then so I can test his blood when needed.
You need to buy a glucometer now since your cat is on insulin. Don't wait till you see the vet. We have lots of handy tips and videos for home testing.
Click on these handy links:
http://www.felinediabetes.com/FDMB/threads/testing-and-shooting-tips.85113/
http://www.felinediabetes.com/FDMB/threads/hometesting-links-and-tips.287/
If you are in the U.S. many of us use an inexpensive glucometer like Walmart's Relion Micro or Confirm meter and strips. For lancets, starting out, we suggest using a size 26 . The glucometer kits like Relion come with 30 or 31 size lancets, which is harder to use in the beginning.
No need to bring in your cat for a glucose curve in 3 weeks. You can do that at home, save your cat needless stress at the vet, and save yourself money.
Vet glucose levels tend to be higher, often 100 points or more, especially with a stressed cat. That is why home testing is crucial. Correct dosing needs to be based on home testing glucose values, not vet values.
We have a terrific Prozinc forum here:
http://www.felinediabetes.com/FDMB/forums/prozinc-pzi.24/
When did you start insulin? Which Fancy Feast are you feeding? Dry food is not good for diabetic cats. Slowly transitioning them off and solely canned/wet food under 10% carbs is important. But you need to be home testing first.
Here's a chart to foods to select from. Look for under 10% carbs :
http://www.catinfo.org/docs/FoodChartPublic9-22-12.pdf
And here's a handy guide for transitioning your kitty off dry food including "Transitioning Dry Food Addicts":
http://catinfo.org/