lantus regulating a cat

[Anastasia]

Hello
I am trying to regulate a cat who was diagnosed about 4 weeks ago. She started on 2 units twice per day her numbers were in 500. Dose was increased to 3 units and numbers went down to 300.
Last week we increased dose to 3.5 units twice per day and her numbers very unstable one days does down to 150 and next day its 450? What to do? Why her numbers jump like that daily?

 

[Larry and Kitties]

Since Lantus is a depot insulin it takes about 5 days on a constant does to see the full effect of that dose. However, you only held the 2 units for two days.
When increasing dose and you get erratic BG that typically means that either the dose is too high or that there other problems causing the erratic BG.
I myself would go to 1 unit twice daily and see what happens.