If your cat is showing signs of low blood sugar, the immediate step is to rub a small amount of honey, corn syrup, or a dextrose gel onto their gums, then contact your veterinarian. Low blood sugar (hypoglycemia) can become life-threatening quickly in cats, so acting fast at home buys critical time while you arrange professional care.
Recognizing the Signs
Low blood sugar in cats produces a range of symptoms that tend to escalate. Early signs include unusual lethargy, weakness, and a wobbly or uncoordinated walk. Your cat may seem anxious, pace around, or vocalize more than normal. Some cats tremble visibly or vomit.
As blood sugar drops further, symptoms become more serious: collapse, apparent blindness, seizures, and eventually loss of consciousness. Severe hypoglycemia, defined as blood glucose falling to around 18 mg/dL or lower, is a medical emergency because the brain depends on a constant supply of glucose from the bloodstream. Normal fasting blood sugar in cats falls roughly between 75 and 117 mg/dL, so any reading well below that range warrants concern.
What to Do Right Now
If your cat is conscious and not seizing, rub honey, corn syrup, or a pharmacy dextrose gel directly onto their gums and under their tongue. The recommended amount is about 1 gram of glucose per kilogram of body weight. For a typical 10-pound (4.5 kg) cat, that works out to roughly one tablespoon of corn syrup or honey. You don’t need to be exact. A generous smear across the gums absorbs quickly through the oral tissues and can raise blood sugar within minutes.
If your cat is alert enough to eat, offer a small amount of their regular food right after applying the syrup. Protein and fat in the food help stabilize blood sugar beyond the initial sugar boost.
If Your Cat Is Seizing or Unconscious
Do not put your fingers, food, or liquid into the mouth of a cat that is convulsing or unresponsive. You risk being bitten, and the cat can inhale fluid into their lungs, causing aspiration pneumonia. Instead, gently rub a thin layer of corn syrup or honey onto the outside of the gums or lips using a fingertip, keeping your hand away from the teeth. Then transport to an emergency veterinary clinic immediately.
Common Causes of Low Blood Sugar in Cats
The most frequent cause in adult cats is an insulin dosage that’s too high relative to how much the cat ate. If your diabetic cat skipped a meal or ate less than usual but still received a full insulin dose, blood sugar can plummet. Other triggers include accidentally giving insulin twice (a common mistake in multi-person households), a change in food that alters carbohydrate intake, or unusual physical activity.
Less commonly, hypoglycemia in cats stems from conditions unrelated to diabetes, such as liver disease, certain tumors that produce insulin-like substances, or severe infections. Kittens are also more vulnerable because they have small glycogen reserves and can develop low blood sugar simply from not eating for several hours.
After the Immediate Crisis
Once you’ve applied sugar to the gums, watch your cat closely. Most cats start to perk up within 5 to 15 minutes as glucose absorbs through the oral membranes. When they seem alert, encourage them to eat a normal meal. Monitor their behavior for the next several hours, as blood sugar can dip again after the initial sugar wears off.
Even if your cat bounces back quickly, contact your veterinarian. A hypoglycemic episode usually signals that something in the management plan needs adjusting, whether that’s the insulin dose, the feeding schedule, or the type of food. Your vet may want to recheck blood glucose curves or modify the treatment protocol to prevent it from happening again.
Keeping Emergency Supplies on Hand
If your cat is diabetic, keep a bottle of corn syrup or a tube of dextrose gel somewhere accessible at all times. Honey works in a pinch but is slightly thicker and harder to spread on gums. Corn syrup is inexpensive and easy to apply. Dextrose gel tubes, sold at most pharmacies in the diabetes supply aisle, are designed specifically for this purpose and come in convenient squeeze packaging.
It also helps to keep a written log of insulin doses and feeding times, especially if more than one person in your household handles injections. Double-dosing is one of the most preventable causes of hypoglycemia, and a simple checklist on the refrigerator can eliminate it.
Preventing Future Episodes
The single most important prevention strategy is making sure your cat eats before receiving insulin. If your cat refuses food or eats significantly less than usual, skip or reduce the insulin dose and call your vet for guidance. Never give a full dose of insulin to a cat that hasn’t eaten.
Consistent feeding times matter. Cats on insulin do best with meals at regular intervals that align with their injection schedule. Switching foods without veterinary input can also cause unexpected blood sugar swings, since different formulas vary widely in carbohydrate content. If you’re using a home glucose monitor, checking your cat’s blood sugar before each injection gives you a real-time safety net. Many veterinarians recommend this for cats on insulin, and portable meters calibrated for feline blood are available through veterinary clinics.