In non scientific terms. when a cat's body perceives a blood glucose level lower than it is used to, it dumps more glucose in the system. So there is extra glucose which usually means the next preshot will be higher. With some cats, a bounce lasts a few hours. With others, a full cycle; with some several cycles. Sometimes with ProZinc, it works best to shoot a lower dose into a pre shot that represents bouncing (because it is sort of an artificial number) Sometimes it works fine to give the dose that number would normally require. Unfortunately there is no answer that fits all cats - it varies. Some ProZinc kitties who went to Lantus continued to bounce; some did better. Again, no way to know. She does drop a lot, from 27 to 8.5 is a huge drop. It might be that Lantus would give you a flatter cycle.