We have a 15 year old who started recently. Once we found the correct dosage it made a huge difference in his overall behavior. I found the testing to be trickier than administering the insulin. Ultimately I settled on the tester below, and found it easiest to get the blood sample from the ear tip. After about a week, we developed a good system for the testing as well. Best of luck!
AlphaTRAK 3, 8 Piece Pet Blood Glucose Monitoring Kit for Diabetic Cats and Dogs, All-in-One Solution for in-Clinic Or at Home, with Digital Results https://a.co/d/gvL9AcS