Breed data

Dog pregnancy by breed size

Pregnancy lasts about the same in a Chihuahua and a Great Dane. What changes with size is how many puppies she carries and how likely a difficult birth is.

Updated October 2026 · Information only, not veterinary advice

Averages by size group

SizeBreeds in databaseAverage litterRangeBreeds with high C-section risk
Toy263.01 to 642%
Small504.21 to 824%
Medium615.42 to 105%
Large577.04 to 120%
Giant207.74 to 1515%

Figures are averaged from the breed database behind the calculator. Individual dogs, lines and ages vary a lot, so use the numbers as a guide. Browse the full list on litter size by breed.

What this means in practice

SizeWhat to plan for
Toy and smallSmall litters, sometimes a single large puppy. Chat to your vet about C-section risk and low blood sugar and calcium after birth.
MediumMid-sized litters. Most births go normally, with the usual X-ray at day 55 to 58.
Large and giantLarge litters can run long, with rests between puppies. Plan for a longer labor and a big whelping area.

Questions

Frequently asked questions

Do small dogs have shorter pregnancies?

Not by a meaningful amount. Gestation is about 63 days from ovulation in dogs of every size. What changes with size is litter size, the number of puppies and the risk of difficult birth.

Which size of dog has the biggest litters?

Large and giant breeds have the largest litters on average. Toy breeds have the smallest, often two to four puppies.

Do small dogs need C-sections more often?

Some do. Flat-faced small breeds such as Bulldogs and Boston Terriers have the highest rates. Many toy breeds also have more trouble with a single large puppy.

Is it harder to count puppies in a large litter?

Yes. Ultrasound counts become less reliable as the litter grows, so an X-ray around day 55 to 58 is the best way to know how many to expect.

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