That is a huge jump, but definitely a more reassuring number. Unfortunately, I don't have any experience with Lantus, but since it's a slower-acting insulin, I am assuming there is a chance he could start decreasing again as the food and Karo start wearing out and the insulin kicks in. I would continue to test fairly regularly to make sure he stays safe. I'm so sorry. I feel so useless, not having any experience to help you out with any certainty, but I just wanted to let you know you weren't alone at least.

Hopefully someone more knowledgeable comes along shortly!