Queen Gestational Diabetes: Week 5–7 Urine Screening and the 48-Hour Recheck

A queen 40 days pregnant can walk into the clinic with a blood glucose of 320 mg/dL, a urine strip reading 3+ glucose, and no diabetes at all. The feline renal threshold sits near 270 mg/dL, and a car ride plus a strange room can push glucose past 300 mg/dL by itself. The week 5 to 7 urine test many catteries run is not a test for "gestational diabetes". It is a test for a queen whose glucose handling was already abnormal before mating, and the result only counts when paired with fructosamine and a second sample.

The label is borrowed from dogs

In dogs, gestational diabetes is a real, reversible diagnosis with published case series. Feline medicine has no equivalent: reviews of queen pregnancy list eclampsia, metritis, dystocia and fetal loss, but not a pregnancy-specific diabetes that resolves after delivery. When a pregnant queen is glucosuric, the likely causes are pre-existing diabetes unmasked by pregnancy, stress hyperglycemia, obesity-related insulin resistance, or a progestin — megestrol acetate used to postpone heat is a documented cause of feline diabetes, and most cats remit after withdrawal. Pregnancy does make cats mildly insulin resistant: progesterone peaks at 11 to 60 ng/mL, intake rises 25% to 50% by term, and normal gain is 12% to 38% of pre-pregnancy weight. Gestation averages 65.6 days, range 52 to 74.

Why the screen lands in week 5 to 7

No AAFP or AAHA guideline recommends routine urine screening in pregnancy; the timing is a practical compromise. By day 35 to 49 the pregnancy is confirmed, the queen still tolerates a litter tray sample, and there is time for a fructosamine and glucose curve before the last fortnight, when travel is least welcome. Earlier, a positive strip is more likely to reflect a full bladder and a stressful visit; later than day 56, the result arrives too close to term to change management. A first-morning sample is the most concentrated, and post-prandial glucose can run 50 to 80 mg/dL above fasting.

What the strip can and cannot see

Detection limits range from about 20 to 100 mg/dL depending on brand, and sensitive feline-validated strips turn positive near 50 mg/dL. A negative result only means glucose sits below that strip's cutoff, which may be as high as 100 mg/dL, and healthy cats can show trace glucose at normal blood glucose — basal glucosuria. The strip triggers bloodwork; it never makes the diagnosis.

Fructosamine is the tie-breaker

Fructosamine averages glucose over the previous one to two weeks, which a single stressed sample cannot show. The usual reference interval is 175 to 400 µmol/L; newly diagnosed diabetics usually exceed 400, often 350 to 730. A queen at 320 mg/dL with fructosamine 300 has had one bad morning. A queen at 260 mg/dL with fructosamine 520 has a real problem that pregnancy made visible. Fructosamine reads falsely low with low albumin, and it lags sudden changes, so it is a diagnostic tool, not a glucose meter substitute.

Calcium before glucose

If the queen trembles, pants, paces or seizes, the order changes. Eclampsia can appear from 3 to 17 days before birth as well as during the first weeks of nursing, and it kills faster than hyperglycemia. Total serum calcium below 7 mg/dL confirms it. Treatment is 10% calcium gluconate slowly intravenously over 10 to 30 minutes with ECG monitoring, because a fast push can cause bradycardia and arrhythmia; the dose and rate are the vet's calculation by body weight. Hypoglycemia is the other look-alike, but it usually brings weakness and hunger rather than rigid tetany. Emergency order: airway and temperature, then calcium and glucose on the same sample, then ketones.

The 48-hour recheck

Whatever the week 5 to 7 result, the 48 hours after birth are the highest-risk window, because insulin resistance falls abruptly once the placentas are delivered. A dose that controlled her on day 60 can drive her hypoglycemic on day 2. Check five things: rectal temperature (normal 38.1 to 39.2 °C; 39.4 °C or above is fever), mammary glands for heat and pain, lochia (red to black and non-odorous is normal for up to 3 weeks), appetite and hydration, and glucose plus ketones if she was flagged. Metritis appears between day 1 and day 10 with depression, fever and foul discharge; mastitis shows hot, painful glands and kittens refusing that side. Neither is caused by diabetes, but both push glucose up.

Clearing her for the next mating

The normal interval — one full cycle after weaning, 6 months between births in most catteries — is covered in our guide to postpartum heat and rebreeding gaps. A queen with a glucose problem needs three gates before that clock starts: fructosamine back within 175 to 400 µmol/L, no glucosuria on two separate samples, and four weeks off insulin with stable weight. If she needed insulin, let the vet confirm remission rather than assume it; a queen bred back while still insulin-resistant tends to conceive a smaller litter. Never use megestrol acetate to delay heat in a queen you intend to breed, and after a cesarean add one more cycle to any interval.

A screening card for the cage door

1. Day 0: record mating; expect birth at 63 to 65 days, with 52 to 74 still normal.
2. Week 3 to 4: ultrasound; a heartbeat is visible from about day 21 to 25.
3. Week 5 to 7: urine glucose and ketones, weight, body condition; fructosamine if positive.
4. Week 7 to birth: weigh weekly; total gain should reach 12% to 38%.
5. Day −3 to day 21: watch for tremors; eclampsia can strike before birth too.
6. 48 hours after birth: temperature, glands, discharge, appetite, glucose if flagged.
7. Week 8 to 10: weaning; repeat fructosamine before any rebreeding decision.

Call the vet today if

• She seizes, trembles continuously, or cannot stand.
• Temperature is 39.4 °C or higher with foul discharge.
• Urine shows glucose and ketones, or she vomits and stops eating.
• Glucose is over 300 mg/dL with weight loss despite a good appetite.
• Two or more kittens die in the first week, or one gland is hot and painful.

This article does not replace veterinary diagnosis. Glucose, calcium, fructosamine and ketones must be read together, with her history, by a vet who can examine her. Do not change an insulin dose, give calcium, or delay a visit based on a home urine strip.

Frequently asked

Related guides

• Metritis in Queens: The First 72 Hours After Birth
• Queen Eclampsia: The Postpartum Calcium Crash
• Retiring a Queen: Age 6-8, Two Litters a Year, Then Spay
• False Pregnancy in Queens: Signs and Testing
• Postpartum Queen Care: Lochia, Mastitis, Eclampsia
• Timing a Queen's C-Section: Progesterone and Fetal Heart