How long are dogs pregnant?
About 63 days, or 9 weeks [5][7][9]. How precise that is depends on what you count from:
| Counted from | Average | Range |
|---|---|---|
| First mating date | 63 days | 56–72 days [5][1][7][9] |
| Ovulation date | 63 days | 61–65 days [1][7][9] |
| LH surge date | 65 days | 64–66 days [3][7] |
The mating date is the least precise, because a female can mate days before she ovulates. Breeding dates don’t predict whelping as closely as ovulation does [3][9]. Vets find the ovulation date or the LH surge with progesterone blood tests; if you have one of those dates, pick it under “The date is the”.
| Source | What it says |
|---|---|
| VCA Animal Hospitals [5] | 57–65 days, average 63 |
| Merck Vet Manual (table) [1] | 58–72 days from breeding; 62–64 from ovulation |
| American Kennel Club [7] | 58–72 days from first breeding; 63 from ovulation; 65–66 from the LH surge |
| Cornell vet school [9] | 63 ± 7 days from first breeding; 63 ± 1–2 from ovulation |
| Merck Vet Manual [3] | 64–66 days after the LH peak |
Worked example
A dog mated on February 10, 2027 is due about April 14, 2027, but could whelp anywhere fromApril 7, 2027 to April 23, 2027. If February 10, 2027 was her ovulation date instead, the window narrows toApril 12, 2027–April 16, 2027. With two matings, VCA suggests expecting puppies 63–65 days after them[5]: enter the second date as well.
When can a vet confirm the pregnancy?
| When | What |
|---|---|
| Day 21–35 | A vet may feel the pregnancy. Abdominal palpation works roughly days 21–35; results vary. [4][5][7] |
| Day 22–30 | Relaxin blood test possible. From about day 22–30 (Merck: after 22–27 days; AKC: about 27–30 days after breeding). [4][7] |
| Day 25–35 | Ultrasound possible. Best from about day 25–35; scans after day 28 are reliable. [4][5][7] |
| Day 42–45 | Skeletons start to show on X-ray. Puppy skeletons become visible around day 42–45. [4][7] |
| Day 55 | X-ray to count puppies. Most accurate after about day 55. [4][7][5] |
An X-ray late in pregnancy is the best way to count the puppies, so you know how many to expect[5][4]. A drop in rectal temperature, often below 99 °F, usually comes within the 24 hours before labor [9][7], though it isn’t always noticed [9].
Dog heat cycle calculator
The heat cycle tab takes the first day of her last heat and shows the typical stage dates and when the next heats are likely to start. It describes what the sources say is typical; it can’t tell you when a particular dog will ovulate, which only a vet’s tests can.
How often do dogs go into heat?
Most dogs come into heat about twice a year [6][8], on average every 7 months[3]. Anywhere from 4 to 13 months between heats is normal [3]; Cornell gives 5–11 months and AKC 6–12 [8][7]. Small breeds may cycle three times a year and giant breeds only once [6], and Basenjis and Tibetan Mastiffs usually cycle once a year [8].
| Source | What it says |
|---|---|
| Merck Vet Manual [3] | Every 4–13 months (average 7); proestrus and estrus each 3 days to 3 weeks, average 9; diestrus 2–3 months; anestrus 1–6 months |
| VCA Animal Hospitals [6] | Usually twice a year; small breeds up to three times, giant breeds once; estrus about 9 days (2–24) |
| Cornell vet school [8] | Two heats a year, every 5–11 months; proestrus 6–11 days; estrus 5–9 days (1–20); anestrus about 4 months; Basenji and Tibetan Mastiff once a year |
| American Kennel Club [7] | Every 6–12 months; proestrus 6–11 days; estrus 5–9 days; both can range 3–21 days; anestrus about 4 months |
The four stages
- Proestrus (day 1 to about day 9): swelling and bloody discharge. Averages about 9 days but can last 3 days to 3 weeks [3][8][7].
- Estrus (typically about days 10–18): the “standing heat,” when she accepts a male. About 9 days on average, from 2 to 24 days [3][6][8].
- Diestrus: about 2–3 months when she isn’t pregnant [3], with progesterone rising and then slowly falling [8][7].
- Anestrus: the rest before the next heat, usually about 4 months [8][7]and from 1 to 6 months [3].
For example, a heat that started on January 5, 2027 would typically be in estrus from about January 14, 2027 toJanuary 22, 2027, but with a short or long proestrus estrus could begin anywhere fromJanuary 8, 2027 to January 26, 2027. Her next heat would most likely start between July 5, 2027 and August 5, 2027.
If you know her own pattern, the tab can use her last two heats or a number of months instead of the average. Young dogs can take up to two years to settle into regular cycles [6].
Common questions
How many weeks is a dog pregnant?
About 9 weeks: 63 days [5][7].
Can I work out the due date from the mating date?
Yes, but expect a wide window: 56 to 72 days after the first mating [5][1][7][9]. An ovulation date from your vet narrows it to a few days.
How long does a dog stay in heat?
The visible part (proestrus and estrus) usually lasts about 2–3 weeks: Cornell puts the bloody discharge at 14–21 days [8], and proestrus and estrus each average about 9 days [3][6].
When does a puppy have her first heat?
On average at about 6 months [6], but anywhere from 6 to 24 months; small breeds tend to start earlier and large breeds later [8][2].
This page gives typical dates for planning and understanding, not breeding, medical or veterinary advice. Talk to your vet about your dog’s pregnancy, heat cycles or spaying.
Sources
- Merck Veterinary Manual, table “Approximate Gestation Periods”Gestation by species; dog 62–64 days from ovulation, 58–72 days from breeding
- Merck Veterinary Manual, table “Features of the Reproductive Cycle”Estrous cycle lengths (cattle 18–24, sheep 14–20 days); dog puberty 6–24 months
- A. P. Davidson, “Breeding Management of Bitches,” Merck Veterinary Manual (reviewed 2025)Heat interval 4–13 months (average 7); proestrus and estrus 3 days to 3 weeks (average 9); diestrus, anestrus; whelping 64–66 days after the LH peak
- A. P. Davidson, “Pregnancy Determination in Bitches and Queens,” Merck Veterinary Manual (reviewed 2025)Palpation, relaxin test, ultrasound and X-ray timing in dogs
- C. Barnes, M. Weir, E. Ward, “Breeding for Pet Owners: Pregnancy in Dogs,” VCA Animal HospitalsDog gestation 57–65 days, average 63; palpation, ultrasound and X-ray timing
- M. Weir, R. Llera, C. Yuill, “Estrous Cycles in Dogs,” VCA Animal HospitalsHeat about twice a year; estrus about 9 days (2–24); first heat about 6 months
- H. Meyers, “The Reproductive Cycle in Dogs: From Breeding to Birthing,” American Kennel Club (2025)Gestation counted from ovulation, LH surge and breeding; heat stage lengths; pregnancy milestones
- Cornell Richard P. Riney Canine Health Center, “Dog estrous cycles” (2023)Heat interval, stage lengths, breed exceptions
- Cornell Richard P. Riney Canine Health Center, “The normal whelping process”63 days from ovulation, 63 ± 7 from first breeding; temperature drop within 24 hours