Cat Blood Glucose Levels Chart (Normal, Diabetic & Target Ranges)
Reference chart of cat blood sugar levels in mg/dL and mmol/L: normal range, stress hyperglycemia, diabetic thresholds, insulin targets, and fructosamine values.
Quick answer: Normal blood glucose for a cat is roughly 70 to 150 mg/dL (3.9 to 8.3 mmol/L). Stress alone can push a healthy cat to 200 to 300 mg/dL temporarily. Persistent readings above about 250 to 300 mg/dL with glucose in the urine and classic signs suggest diabetes. Below 60 mg/dL is hypoglycemia and an emergency in a cat on insulin. Interpretation and any insulin change belong to your veterinarian.
This chart summarizes the blood sugar numbers veterinarians use when screening senior cats and managing feline diabetes. It is a researched reference for owners, not veterinary advice: laboratories publish their own ranges, meters vary, and only your vet can interpret your cat's values in context. Use it to understand results, prepare questions, and recognize emergencies. For the full disease overview, start with our guide to diabetes in senior cats.
Cat Blood Glucose Levels Chart
| Blood Glucose (mg/dL) | mmol/L | Interpretation | What to Do |
|---|---|---|---|
| Below 60 | Below 3.3 | Hypoglycemia, dangerous, most often from insulin overdose | Emergency: corn syrup on the gums, call the vet now |
| 60 to 70 | 3.3 to 3.9 | Borderline low | Feed, recheck soon, report to your vet the same day |
| 70 to 150 | 3.9 to 8.3 | Normal range for most healthy cats | No action, continue routine monitoring |
| 150 to 250 | 8.3 to 13.9 | Mildly elevated, very often stress hyperglycemia | Recheck when calm, mention at the next vet visit |
| 250 to 290 | 13.9 to 16.1 | Renal threshold zone, glucose begins spilling into urine | Vet visit for urine testing and fructosamine |
| 290 to 400 | 16.1 to 22.2 | Strongly suggests diabetes when persistent with signs | Prompt vet workup and treatment plan |
| Above 400 | Above 22.2 | Marked hyperglycemia, risk of diabetic ketoacidosis | Urgent vet care, same day if the cat is unwell |
To convert units, divide mg/dL by 18 to get mmol/L. Values are compiled from widely published veterinary reference ranges, and your laboratory's printed range takes precedence. A single reading is a snapshot; trends and repeat values matter far more than any one number.
Target Ranges for Diabetic Cats on Insulin
| Measurement | Typical Target | Notes |
|---|---|---|
| Overall daily range | About 80 to 300 mg/dL | Goal for most of a 12-hour insulin cycle |
| Nadir (lowest point of curve) | About 80 to 150 mg/dL | Usually 4 to 8 hours after dosing, varies by insulin |
| Pre-insulin (highest point) | Ideally under about 300 mg/dL | Persistent higher peaks suggest a dose or diet review |
| Action threshold, low | Under 80 mg/dL | Call your vet before the next dose |
| Emergency, low | Under 60 mg/dL | Corn syrup on gums, emergency vet |
These are general veterinary targets, not instructions. Your vet sets specific numbers for your cat and adjusts them over time, especially if remission is the goal. Never change an insulin dose based on this chart. Many owners check glucose at home with a pet-calibrated meter using a drop of blood from the ear margin, or use a continuous glucose monitor placed by the vet, which removes clinic stress from the readings.
Fructosamine Levels Chart
Fructosamine reflects average blood glucose over the previous one to two weeks, so it is not fooled by momentary stress. Vets use it to confirm diabetes and to judge long-term control.
| Fructosamine (umol/L) | Interpretation in a Treated Diabetic Cat |
|---|---|
| Roughly 190 to 365 | Typical non-diabetic range (lab dependent) |
| Under 350 | Possible excellent control, remission, or too much insulin; needs vet review |
| 350 to 450 | Good control |
| 450 to 550 | Fair control, vet may adjust the plan |
| Over 550 | Poor control, treatment review needed |
When to Call the Vet
- Same hour: wobbliness, collapse, twitching, or seizures in a cat on insulin, or any reading under 60 mg/dL. Rub corn syrup or honey on the gums on the way in.
- Same day: a diabetic cat that stops eating, vomits repeatedly, or acts lethargic. These can signal diabetic ketoacidosis, which is life threatening.
- This week: repeated home readings above about 300 mg/dL, a big jump in thirst or urination, or unexplained weight loss. Heavy drinking has several senior-cat causes beyond diabetes; see why an old cat drinks lots of water.
Because early diabetes, kidney disease, and hyperthyroidism share signs, senior cats benefit from routine bloodwork. Our wellness screening schedule shows when to test, and the senior cat normal lab values page covers the rest of the panel. Weight control is the single biggest modifiable risk factor; see weight management for older cats.
Home Monitoring Tools for Diabetic Cats
AlphaTRAK Pet Blood Glucose Monitoring Kit
Calibrated for cats, for accurate at-home blood sugar checks.
Instinct Grain-Free Pate Wet Cat Food
Low-carb, high-protein canned food to support glucose control.
Related Reading
- Diabetes in Senior Cats - Signs, insulin, diet, and the path to remission.
- Senior Cat Normal Lab Values - The full bloodwork panel in one reference.
- Old Cat Drinking Lots of Water - The workup when thirst spikes.
- Old Cat Losing Weight but Still Eating - Why appetite with weight loss is a red flag.
Senior Cat Wellness & Care Planner
Track your aging cat's health, meds, vet visits, mobility, nutrition, and quality of life, all in one printable planner.
Pet Insurance · Sponsored
Protect Your Senior Cat From Surprise Vet Bills
Older cats are more prone to kidney, dental, and thyroid trouble, and a single emergency visit can run into the hundreds or thousands. Pet insurance can help you say yes to the care your cat needs without draining your savings. Get a free quote and see what coverage fits.
Frequently Asked Questions
What is a normal blood glucose level for a cat?
A healthy cat typically runs between about 70 and 150 mg/dL (3.9 to 8.3 mmol/L), though every laboratory publishes its own reference range. Readings drift within that band through the day depending on meals, activity, and stress. A single mildly elevated number does not diagnose diabetes, because stress alone can push a cat well above normal during a vet visit or a home blood draw.
What blood sugar level indicates diabetes in cats?
Persistent readings above roughly 250 to 300 mg/dL, together with glucose in the urine and classic signs like heavy drinking, heavy urination, and weight loss despite a good appetite, point strongly to diabetes. Vets usually confirm with a fructosamine test, which reflects average glucose over the previous one to two weeks and is not affected by momentary stress. Diagnosis always belongs to your veterinarian, not a single meter reading.
Can stress raise a cat's blood sugar?
Yes, dramatically. Stress hyperglycemia is common in cats and can push glucose from normal into the 200s or even near 300 mg/dL within minutes, especially at the clinic. This is why one high reading in a stressed cat is never enough to diagnose diabetes and why vets rely on repeat samples, urine glucose, and fructosamine to separate a stressed cat from a truly diabetic one.
What blood sugar is dangerously low for a cat?
Readings below about 60 mg/dL are hypoglycemia and become an emergency as they fall, particularly in a cat receiving insulin. Signs include wobbliness, weakness, glassy eyes, twitching, and seizures. If a diabetic cat shows these signs, rub a little corn syrup or honey on the gums and call your veterinarian or an emergency clinic immediately. Never give more insulin to a cat that is acting abnormal without checking glucose first.
What is a good glucose range for a diabetic cat on insulin?
Most veterinarians aim to keep an insulin-treated cat roughly between 80 and 300 mg/dL through the day, with the lowest point of the curve, the nadir, ideally landing around 80 to 150 mg/dL. Exact targets vary by cat, insulin type, and remission goals, so the numbers your vet sets for your cat override any general chart. Never adjust an insulin dose on your own based on one reading.
What is a normal fructosamine level for a cat?
Non-diabetic cats generally run roughly 190 to 365 umol/L, depending on the laboratory. In treated diabetics, values under about 450 umol/L usually reflect good control, 450 to 550 fair control, and over 550 poor control. A very low fructosamine in a treated cat can signal too much insulin or the start of remission, both of which need prompt veterinary review.
Can cats with diabetes go into remission?
Yes. A meaningful share of newly diagnosed cats achieve remission, meaning normal glucose without insulin, especially when treatment starts early and combines insulin with a low-carbohydrate wet diet and weight control. Remission is most likely in the first few months after diagnosis. Cats in remission still need monitoring for life, since relapse is possible, particularly after illness or steroid treatment.
Need more help with your aging cat?
Browse our guides by topic to find practical solutions.
Wellness Planner: $39