The Temperature Drop Before Whelping
Of every labor sign, one arrives first and lies least: her temperature. This guide covers the routine that makes the drop visible — twice-daily readings from day 56 — what counts as a real drop, and what to do in the 24 hours after you see it.
Why temperature at all?
Through most of pregnancy her temperature sits at the normal dog baseline, roughly 101–102.5 °F (38.3–39.2 °C). In the final day before labor, the progesterone that has sustained the pregnancy falls away — and her temperature falls with it, by about 1–2 °F, typically to below 99 °F (37.2 °C). The drop is brief: the temperature often climbs back up as labor begins. Miss the twice-daily routine and you can miss the whole signal.
The routine (from day 56)
Twice a day, the same two times — say 8 a.m. and 8 p.m. — logged in the notebook by the whelping box. Your whelping date calculator gives the exact calendar date day 56 falls on. Three or four days of readings establish her personal baseline, which matters more than the textbook number: a dog whose normal is 101.0 °F dropping to 99.4 °F has told you less than a 102.3 °F dog dropping to 100.8 °F — watch the size and direction of the fall, confirmed by a second low reading.
When the drop lands
Expect stage 1 within roughly 12–24 hours: restlessness, nesting, appetite loss, panting — the labor signs arriving in their order. Your jobs are simple: stay home or stay close, keep her world quiet, offer water, make sure the box is ready and warm, and put the vet's number on top of the notebook. Then let her work — most dogs stage-1 through the evening and deliver overnight.
Drops that mislead
A single low reading followed by a normal one is usually measurement noise — angle, depth, a wriggle. Confirm before mobilizing. And a drop that comes well before day 56, or with illness signs (vomiting, diarrhea, lethargy, discharge), is not a labor sign at all — that combination is a vet call, whatever the calendar says.
Day 56 is a date, not a vibe: find yours on the canine pregnancy calendar, where the temperature-check start is already flagged.
Frequently asked questions
How do I take my dog's temperature?
Rectally, with a digital thermometer and a little water-based lubricant: lift her tail, insert the tip about an inch (less for small dogs), hold it still until it beeps, read, clean. Most dogs tolerate it well with a helper, calm handling and a treat after. Take it at the same times each day.
What if her temperature drops but nothing happens?
Give it the stated window: the drop predicts labor within about 12–24 hours, not within the hour. Keep her close, keep the box ready, and re-check every few hours. If 24 hours pass with no stage 1 signs at all, a call to the vet for reassurance is reasonable.
My dog's temperature went up and down. Which reading counts?
Look for a sustained drop confirmed by a second reading an hour or two later, not a single dip. Baselines vary by time of day — another reason the routine is twice daily at fixed times from day 56, so you are comparing like with like.