These are high BGs, even the numbers in the 300s at home when she's not stressed. Normal BG on a human meter is around 50 to 120 and on a pet meter around 70 to 150.
Is she completely switched to a low carb wet food? If so, get some BG tests done. There's no avoiding it if you want to get her under control ASAP. If the numbers are high she should be started on insulin. The sooner you get her BG under good control the better your chances of her going into remission. Many people are reluctant to test BG but it's the single best tool for helping your kitty. There's a lot of good info here:
http://www.felinediabetes.com/FDMB/threads/hometesting-links-and-tips.287/
Here's a new member's handout I made up. Read it over a few times and post any/all questions you have here. We have members with all sorts of difficulties from disabilities to semi feral kitties so we can help.

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It would help us if you set up your signature (light grey text under a post). Here's how:
- click on your name in the upper right corner of this page
- click on "signature" in the men that drops down
- type the following in the box that opens: kitty's name/age/date of diabetes diagnosis/insulin you're using /glucose meter you're using/what he eats/any other meds or health issues he has.
Another thing that will help us help you now that you've started BG testing at home is to set up a spreadsheet like the one we use here. We can all see it and look at it before offering advice:
http://www.felinediabetes.com/FDMB/threads/fdmb-spreadsheet-instructions.130337/
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Here's the basic testing routine we recommend:
- test every day AM and PM before feeding and injecting (no food at least 2 hours before) to see if the planned dose is safe
- test at least once near mid cycle or at bedtime daily to see how low the BG goes
- do extra tests on days off to fill in the response picture
- if indicated by consistently high numbers on your spreadsheet, increase the dose by no more than 0.25 u at a time so you don't accidentally go right past a good dose
- post here for advice whenever you're confused or unsure of what to do.
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Here's an explanation of what we call "bouncing". It explains why a kitty's BG can go from low to sky high:
- BG goes low OR lower than usual OR drops too quickly.
- Kitty's body panics and thinks there's danger (OMG! My BG is too low!).
- Complex physiologic processes take glycogen stored in the liver (I think of it as "bounce fuel"), convert it to glucose and dump it into the bloodstream to counteract the perceived dangerously low BG.
- These processes go into overdrive in kitties who are bounce prone and keep the BG propped up varying lengths of time (AKA bouncing).
- Bounce prone kitty repeats this until his body learns that healthy low numbers are safe. Some kitties are slow learners.
- Too high a dose of insulin can keep them bouncing over and over until the " bounce fuel" runs out and they crash - ie., have a hypo episode. That's why we worry so much about kitties that have had too high a starting dose prescribed by the vet and the owner isn't home testing.
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Here are some tips on how to do urine ketone testing (VERY important if BG is high and kitty isn't eating well!):
- put the end of the test strip right in his urine stream as he's peeing
- slip a shallow, long handled spoon under his backside to catch a little pee - you don't need much
- put a double layer of plastic wrap over his favourite part of the litter box and poke some depressions in it too catch pee.
Most test strips have to be dipped and allowed to develop for 15 seconds before viewing the colour change in very good light.