If your cat is testing in low numbers and you are not getting a quick response to your post, there are several things you need to do. (Low numbers are under 50mg/dL or 2.8 mmol/L.)
Depending on how carbohydrate sensitive your cat is, feed approximately a teaspoon or less of gravy from high carb food or high carb food only.
(If you have a cat with GI issues, using a couple of drops of syrup plus low carb food is an alternative.)
Test again in 15 – 20 min. Depending on the numbers, give more HC food.
Repeat the above steps every 15 – 20 min. until your cat tests in the 50 mg/dL (2.8 mmol/L) or above range for 2 consecutive tests. Continue to feed in small amounts to keep numbers in a safe range.
Test in 30 - 40 min. and repeat the test and feed process until there are 2 consecutive tests where numbers are stable or rising.
Test in an hour and follow the same steps.
DO NOT become complacent. If number have risen after one or two tests, it’s important to continue testing. Numbers may bobble up and down as the HC food and/or Karo wear off. DO NOT get one test where your cat has risen from low numbers into the 50s and go to sleep or leave the house. You are putting your cat in a risky situation. When in doubt, leave HC food out.
In the case of an accidental overdose or should there be symptoms of hypoglycemia, even if you have caught this in the early stages, you may need to monitor for literally 16 or more hours. Lantus and Levemir are long acting types of insulin. This means if your cat is over dose, you will need to stay alert for hours in order to closely monitor and to keep your cat safe.