Dog Pregnancy Calculator

How the Dog Pregnancy Calculator Works

The dog pregnancy calculator (4,400 monthly searches, CPC $6.22 — indicating high-intent searches from breeders) estimates the expected whelping (birth) date from the mating date. The related "dog gestation calculator" adds 1,600 more monthly searches. Canine gestation is approximately 63 days from ovulation, or 58–68 days from first mating. The most precise measurement: from the LH (luteinizing hormone) surge, 2 days before ovulation — but this requires progesterone blood testing at a veterinarian.

For practical purposes: add 63 days to the first breeding date for an estimated whelping date, normal range Day 58–68. Most litters arrive between Days 60–65. Smaller breeds may deliver a day or two earlier; giant breeds may go to Day 66–68. Keep within ±3 days of your estimate as "normal" — outside that range, contact your veterinarian.

Canine Pregnancy Timeline by Week

• Week 1 (Days 1–7): Fertilization occurs; embryos begin cell division while still in oviducts. No visible changes.
• Week 2 (Days 8–14): Embryos implant in uterine horns. Still no external signs.
• Week 3 (Days 15–21): Embryo organs begin forming. Ultrasound can detect pregnancy by Day 25–28.
• Week 4 (Days 22–28): Embryos approximately 1 cm; heartbeats visible on ultrasound. Nipples may enlarge, slight behavioral changes.
• Week 5 (Days 29–35): Puppies develop gender characteristics; claws and whiskers form. Morning sickness may occur.
• Week 6 (Days 36–42): Abdomen visibly expands. Appetite increases. Radiograph can now count puppies by Day 45+ (bones visible).
• Week 7 (Days 43–49): Puppies nearly fully formed. Dam begins producing milk. Nesting behavior may start.
• Week 8 (Days 50–56): Puppies fully developed. Dam seeks nesting spot. Vulvar discharge may appear (clear).
• Week 9 (Days 57–63+): Whelping imminent. Temperature drop to below 99°F (37.2°C) signals birth within 24 hours.

Preparing for Whelping

Set up a whelping box 1–2 weeks before the due date in a quiet, warm location (80–85°F for newborns). The box should be large enough for the dam to stretch out, with low sides for easy entry/exit but high enough to contain newborns. Line with newspaper (easily replaced) topped with clean towels. Have on hand: a thermometer, bulb syringe, clean towels, scissors and dental floss for cords, iodine for cord stumps, digital scale for puppy weights, and your vet's emergency number.

Frequently Asked Questions

How many puppies should I expect?

Average litter size varies by breed: Chihuahuas average 1–3 puppies; Labrador Retrievers average 7–8; German Shepherds average 5–9. Smaller breeds have smaller litters; larger breeds generally larger. First litters are typically smaller than subsequent ones. An x-ray at Day 45–55 can count skeletal puppies to give you an accurate number to expect.

When should I take my pregnant dog to the vet?

Confirm pregnancy at 3–4 weeks post-breeding via ultrasound. Schedule a prenatal wellness exam. At Day 45+, an x-ray can count puppies. If whelping hasn't started by Day 65, contact your vet. During whelping: seek emergency care if active pushing exceeds 30–60 minutes without a puppy, if more than 4 hours pass between puppies, if green discharge appears before the first puppy, or if the dam shows extreme distress or weakness.

How do I know when my dog is about to give birth?

Signs within 24 hours of whelping: rectal temperature drops from normal (101–102.5°F) to below 99°F (37.2°C) — the most reliable sign; measure twice daily from Day 58 onward. Other signs: restlessness, nesting, loss of appetite, shivering, panting, and clear vaginal discharge. Labor itself has three stages: uterine contractions (visible restlessness), puppy delivery, and placenta delivery.