The occurrence of signs depends on how far the bg drops and on how fast the blood glucose drops. Owners of diabetic cats have also reported observing these signs sleepiness unable to wake the cat easily when it is sleeping. This means they do not show any of the usual signs of hypoglycemia even though their bg is very low. Read experiences of three pets who have had episodes of asymptomatic hypoglycemia. Always have corn syrup or sugar available.
Corn syrup works well because it is a very pure sugar, and it is liquid.
Karo is not available in Canada, but similar corn syrup products are available. Pancake syrup, honey, or table sugar dissolved in some water will also work. Wherever your pet is, there should be an emergency supply of sugar. You should carry sugar with you when you take your pet out of the house, even for a short walk. Packets of honey.