Remission is a real outcome in cats, not a lucky story: a cat that reaches euglycemia and stays off insulin for 4 weeks or more is in remission, and the window where that happens is usually the first 3-6 months after diagnosis. The work is done with 2 numbers and 1 schedule, a 12-hour curve read against a 100-300 mg/dL band, and a recheck every 3 months. Insulin dosing is by veterinary prescription only, and the curve is how your vet adjusts it.
What the 100-300 band actually measures
100-300 mg/dL is the band a treated cat should sit in across most of a 12-hour cycle, not a single fasting number. The low point, or nadir, is the number that decides safety, and most vets aim for a nadir of 100-150 mg/dL. A pre-insulin reading of 250-300 with a nadir of 120 is a well-controlled cat. A pre-insulin reading of 180 with a nadir of 45 is a dangerous one, even though the morning number looked better.
Glucose under 60 mg/dL is a hypoglycemia emergency: twitching, wobbling, glassy eyes or a seizure means a vet now, and never another insulin shot. Above 350 mg/dL for 2 readings in a row means the current plan is not working and the cat needs a curve, not a bigger meal.
The 4-week curve, 7 points over 12 hours
The first full curve is usually done 4 weeks after starting treatment, once the cat has been on a stable diet and a stable prescription for at least 14 days. Seven samples, every 2 hours, from just before the morning shot to just before the evening one. Feed and shoot as normal; a curve taken without the normal routine measures nothing.
| Time | Target mg/dL | What it tells you |
|---|---|---|
| 0 h, pre-insulin | 150-300 | Baseline for the day |
| 2 h | 150-300 | Absorption starting, no sharp drop |
| 4 h | 100-250 | Onset working as expected |
| 6 h | 100-200 | Nadir zone, the number that matters most |
| 8 h | 100-300 | Rising again, duration long enough |
| 12 h | 150-300 | Back to baseline, no overlap |
| Any point | Under 60 | Emergency: stop, call the vet |
Two readings carry most of the decision: the 6-hour nadir and the 12-hour value. A nadir under 80 mg/dL means the prescribed dose is too high for this cat, even if every other number looks acceptable. A 12-hour value below 150 mg/dL with a low nadir means the dose is lasting too long, and the answer is a smaller dose, not a skipped meal.
Three conditions that define remission
Remission is not a feeling, it is a set of conditions, and all 3 have to hold at the same recheck. First, no clinical signs for 4 weeks: normal drinking, normal urination, stable weight, no hunger rages. Second, glucose stays in the 80-200 mg/dL range through a 12-hour curve with no insulin on board, run after the vet has stepped the dose down. Third, fructosamine in the reference range, which is the proof that the 12 hours were not a fluke.
Good candidates share features: diagnosed within the last 6 months, no ketoacidosis at diagnosis, insulin requirement that has already fallen by half, and a cat that is overweight rather than thin. Cats that reach remission usually do it in the first 3-6 months; the diet detail behind that sits in the remission guide. Cats still on a full dose at 6 months can still remit, but the odds are lower.
Feeding rules that decide the outcome
Diet is half the treatment. The target is a canned or pouch food under 10% carbohydrates on a dry-matter basis, high in protein, fed as 2 measured meals timed with the 2 insulin shots. Free-feeding dry food makes the curve unreadable and is the most common reason a cat never remits. Keep the same food, the same times and the same volume for the whole 4 weeks before the first curve; a food change mid-curve wastes the test.
An overweight cat should lose 1-2% of body weight per week, no faster. A 6 kg cat losing 90-120 g a week is on track. Faster loss in a cat that is not eating is a hepatic lipidosis risk and a same-week vet visit, not a diet success. Water intake matters too: a cat that stops drinking normally on a good curve is a cat to re-check, because remission removes the high urine output that was masking poor intake.
Every 3 months, without exception
A stable cat gets a recheck every 3 months: weight, fructosamine, and either a full 12-hour curve or a 3-point spot check at 0, 6 and 12 hours. Add a full blood panel and urine culture every 6-12 months, because urinary infection and kidney disease both push glucose up and are easy to miss in a cat that looks fine. Vaccination in a diabetic cat is also a good moment for a titre check rather than another dose. Between visits, an at-home glucose meter with an ear-prick sample at 2 or 3 fixed times a week is what catches a falling dose requirement before a hypo episode does.
Bring the log, not the memory. Dates, times, the numbers, what the cat ate, and any vomiting or missed meal. A log with 30 or more entries lets your vet shorten the curve and adjust a prescription instead of guessing at one.
When remission is the wrong goal
Stop chasing remission in 3 situations: a cat with a history of ketoacidosis, a cat with concurrent pancreatitis, acromegaly or advanced kidney disease, and a cat whose dose has not moved in 6 months despite good food and good weight. In those cats the aim is stable control in the 100-300 band, no clinical signs, and no hypoglycemia, which is a good outcome on its own.
Any cat that stops eating for 24 hours, vomits 3 or more times in a day, or breathes with its mouth open needs to be seen the same day. Insulin given to a cat that is not eating is how a manageable case becomes an intensive care case. When in doubt, skip the shot and call, and let the vet set the next dose by prescription.
Five steps for the next 12 weeks
- Fix the food, the 2 meal times and the 2 shot times, and change nothing for 14 days.
- Book the week-4 curve before you leave the clinic, with a 12-hour slot on the calendar.
- Record glucose, appetite, water intake and weight in one place, every day, no gaps.
- Ask for the nadir number at every visit, and treat anything under 80 mg/dL as a dose problem.
- Put the 3-month recheck on the calendar now, and repeat it 4 times a year without waiting for symptoms.
Frequently asked
Can my cat really stop insulin completely?
Some cats do, and the usual window is the first 3-6 months after diagnosis. Remission means glucose stays in the 80-200 mg/dL range on a 12-hour curve with no insulin, plus a normal fructosamine and no clinical signs for 4 weeks. It is not permanent for every cat: roughly a third relapse within a year, which is why the every-3-month recheck continues even when the cat looks completely normal.
How often should a glucose curve be run?
One full 12-hour curve at week 4 of treatment, then every 3 months while the cat is stable, and any time the dose changes, the cat stops eating, or 2 readings in a row sit above 350 mg/dL. A curve needs 7 samples every 2 hours on the normal feeding and injection routine; a curve taken after a food change or a missed shot cannot be used to set a dose.
What counts as an emergency during treatment?
Glucose under 60 mg/dL with twitching, wobbling or a seizure is an emergency, and so is a cat that has vomited 3 or more times in a day or refused food for 24 hours. In those cases do not give the next shot and call the vet. Never adjust the insulin dose yourself, because the correct change depends on the nadir and the duration, not on one high morning reading.