How long is a dog pregnant?

About 63 days from ovulation, and about 65 days from the LH surge. From the day of mating the figure is looser, which is why the window on this page is wider.

What if I do not know the exact date she mated?

Use your best date and read the window, not just the single due date. Your vet can narrow it down.

When should I call the vet?

Any time you are worried, and if she goes past the end of the window without whelping. Speak with your vet before the due date about what to expect.

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When is your dog's litter due?

Choose the date you are counting from and see the expected due date and window.

The dates

What you are counting from, and when

Counting from

If there was more than one mating, use the first. The window is wider because mating is not ovulation.

Date

Expected due date

Choose a date and the expected due date appears here.

General information, not veterinary advice

This is arithmetic from published sources. Speak with your vet about your own pet.

The short answer

A dog mated on 1 October is expected to whelp around 3 December, 63 days later, with a window of about 4 days either side. Counting from the LH surge instead, the figure is 65 days, and the window is tighter because the date is more exact.

Days to the expected due date, by starting point
Counting from	Days	Window on this page
Mating	63	4 days either side
Ovulation	63	2 days either side
LH surge	65	1 day either side

The maths

Every formula behind the answer, so you can check it.

Due date

due date = starting date + 63 days (mating or ovulation) or + 65 days (LH surge)

Pregnancy in the bitch is reported as 63 plus or minus 2 days from ovulation and 65 plus or minus 1 days from the LH surge.

Window from mating

due date plus or minus 4 days

A dog can mate days before or after she ovulates, so a mating date is a looser starting point than an ovulation date. The extra 2 days either side, on top of the reported 2, is this page's own choice and is not from the source.

What it leaves out

It cannot confirm a pregnancy. Only your vet can, and they can give a narrower window for your own dog.
It does not know about litter size, breed or age, all of which can move the real date.
It is not advice on caring for her or whelping. Talk to your vet well before the due date.

Sources

Concannon PW. Reproductive cycles of the domestic bitch. Animal Reproduction Science 124(3-4), 200 to 210, 2011. Pregnancy length from ovulation and from the LH surge.