Hello Donna,
Lantus is usually given twice a day (I don't
know of anyone here at the moment who is giving Lantus once a day). Insulin does not usually last much longer than 12 hours in a cat's system. (Cat's metabolize insulin about twice as fast as humans do.)
It may be that Cookie only has insulin in her system for half the day. Also, it may not be working as effectively as it could because Lantus is a 'depot' insulin that needs to build up a little store in the cat's body before it can work to full effect.
It would be good to know what Cookie's blood glucose levels are. Do you feel up to trying a test? I know it probably sounds a bit scary but it may well be easier than you think. You may just surprise yourself! And there is nothing to be lost by
trying...
Just make sure her ears are nice and warm. It'll make it a lot easier.
And please know that this should not hurt Cookie
at all. There are very few nerve endings in the outer edge of the cat's ear.
Have you seen the FDMB page of info on hometesting? The link is here:
Hometesting Links and Tips
Also you may find this page of pics and instructions helpful:
http://www.sugarpet.net/bloodtst.html
I actually found the pictures more helpful than the videos when I was learning to hometest.
I see that you have ketone strips. Did you test Cookie's pee for ketones? And if so, what was the result?
Best wishes,
Eliz