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Canine pregnancy averages 63 days from mating (58-68 is normal, because conception can lag mating by days). A guide, not veterinary advice: book a vet check for pregnancy confirmation and whelping preparation.
What The Dog Pregnancy Calculator Works Out
- Expected whelping date: the mating date plus 63 days, the canine average. From a 1 September mating the whelping date centres on 3 November.
- Likely window: 58 to 68 days from mating, because ovulation and conception can trail the mating itself by several days (sperm survive up to a week in the reproductive tract, which is also why litters can occasionally have more than one sire).
- Key milestones: ultrasound confirmation from day 28 (or a relaxin blood test), the gradual move to puppy food and introduction of the whelping box from week 6, so it is familiar territory by the time it is needed.
- Date entered is (advanced): if the breeding was progesterone-timed, enter the ovulation date instead: whelping is then 63 days later with a window of just plus or minus a day, which is how vets pin the date down precisely.
- Gestation length and mating span (advanced): override the 63-day average (some breeds and individual bitches run consistently shorter or longer) and add the days between first and last mating, which widens the late end of the window.
- Today (advanced): which day and week of the pregnancy it is now and how many days remain, or a warning if the window has passed without puppies.
- X-ray count and temperature checks (advanced): an X-ray after day 55 counts skulls so you know how many puppies to expect; twice-daily temperature checks from day 58 catch the drop below 37.2C that signals whelping within 24 hours. More than two hours of strong straining without a puppy, green discharge before the first arrival, or obvious distress are emergency vet calls.
- Puppies can leave from (advanced): the date the puppies reach the leaving age you choose. UK law bans selling puppies under 8 weeks, and Lucy's Law bans third-party sales; breeders in England need a licence if breeding three or more litters a year or breeding as a business.
- Typical litter size (advanced): a rough expectation by the dam's size: 3 to 4 for small breeds, 5 to 6 for medium and 7 to 8 for large. First litters and older dams tend to be smaller.
- Week-by-week table (advanced): the dates of each of the nine weeks with what to expect and do in each, with the current week marked. A guide, not veterinary advice.
Source and further reading: PDSA pet health advice.