Seems like Frankie's numbers are levelling out now, Sue.
That does look like a bounce to me (
possibly 'aided and abetted' by the Royal Canin food).
If it
is bouncing, then it may be that lowering the insulin dose could help level things out.
I don't use Lantus and so can't advise on Lantus dosing (I use PZI insulin).
I'm hoping that some experienced Lantus folks will be able to give you some advice on dosage soon.
And regarding food, most of us just feed our cats ordinary low carb wet food. The prescription foods are pricey and tend to be too high in carbohydrate.
We recommend that cats are fed a wet/canned diet that has less than 10% of calories from carbohydrates. However, reducing the carb content of the diet can reduce the blood glucose quite a bit in some cats, so (assuming you might want to switch foods) it may be best not to do this at the same time as working out what the current insulin dose is doing for Frankie. Sometimes it's better to do one thing at a time... Alternatively, it
might be possible to change the food
if you also reduce the insulin at the same time; but only if you are able to monitor the effect on Frankie's blood glucose. Let's see what others think...
You may get more eyes on this thread if you edit your title to include something like 'dosing advice needed' (and there is also a little '?' icon you can add if you want). To edit your subject line just look at the top right hand corner of your first message and you'll see 'thread tools'. If you click on that you'll get the option to edit your title.
FYI: There is a fledgling list of suitable UK foods (if you want to switch). It's not exhaustive but it is a pretty long list and is growing. It's currently still in the draft stage. This post tells you how to access it:
Food Forum, Anyone?
Eliz