My Lady is a diabetic. Excessive urination and excessive drinking are the classic signs an owner first notices.
To answer your question, yes, you can check his blood glucose with your meter. I check Lady myself with an Ultra One Touch. Normal blood sugar is similar to humans, between 80-120.
Paw pricks don't work on dogs. The best place to get the drop of blood is inside the lip right above the canine teeth. There is a vein that runs vertically along there plus it is not a very sensitive area. If he is good about having his mouth touched, maybe you can do it.
Here is a step by step that may be helpful:
http://www.sugarcats.net/sites/harry/lipprick.html