You're not doing anything wrong but we do need more details. That's actually a promising number! Blackie is responding well!
While we're working on that, if you're using a human meter, go ahead and feed him a little of his regular food and test again in 30 minutes.
If you're using a pet meter, give him a teaspoon or two of high carb food or add a few drops of Karo/honey/syrup to some food and test again in 20-30 minutes