DOG PREGNANCY DAY BY DAY

(Images annoted 'Bitch 1' were done as an example of how the fetus develop from around
Day 16, which is far too early to confirm pregnancy, and the difference in just a few days)

Day 1
On the first day of mating, dependent on the size, the average male/stud releases around 500 million sperm -
they can produce up to 10 million sperm per pound of bodyweight.
The sperm travels through the cervix to the fallopian tubes, which takes between 45 minutes - 3 hours, here the sperm ripens, which takes around 5 - 10 hours.

Day 2
The sperm look for an egg to fertilize. If the bitch has not ovulated, “normal” dog semen lives another 3-to-7 days in the bitch, 
the better the semen quality, the more leeway there is in ovulation timing.

Day 3
The bitch and male are ready for a second mating

Day 4
By day 4 the first lot of eggs will be fertilized.
In the first trimester you do not need to change anything with the bitch, she can have her usual exercise and food, and normal exercise.

Day 5 - 11
Fertilised eggs will make their way down the fallopian tubes into the uterine horns.

Day 12 - 13
Embryos move around in the fluid filled uterus looking for a suitable place to nest. They measure around 0.5 - 0.8mm.

Day 14
The fetus migrates in the womb and individual embryos are diffused in uterine corners where later the nesting into the uterine wall begins.

Day 15
During the next two weeks, the internal organs of the embryo will develop and you need to take extra care of your bitch.
Do not use any flea treatment or worming products during this period of gestation.
The bitch will be very sensitive to any changes in her normal routine, food, exercise, etc.
Any changes can disrupt the development of the embryo and until day 39, can still be re absorbed.

Day 16
You may notice a change to the dogs nipples, they may become pink and enlarged.
The embryo will measure just over 1mm.


Ultrasound image - arrows pointing to possible fetal sacs

Day 17
Embryos are nesting and the nervous system begins to develop, followed by the head and body.

Day 18
By day 18, the placenta begins to develop along with the nervous system. Size of embryo is about 2 - 3mm.


Ultrasound image again pointing to possible fetal sacs. It is too early to give
a definite pregnancy confirmation and further images of the same bitch will be posted to this
article as pregnancy progresses.

Day 19
Development of the internal organs

Day 20
You may notice a slight discharge from your bitch at this stage which comes from around the placenta.

Day 21
The placenta is formed, the fetus is around 5 - 8mm

Day 22


The bitch may have morning sickness and loss of appetite, together with morning sickness as a result of hormonal changes and tension in the womb.
Divide food into smaller portions, she may also have a clear vaginal discharge

Day 23


The fetus starts to develop eyes, ears, nose, jaw and liver.

Day 24


Due to the rapid development of all major organs, the actual fetal growth is slow.

Day 25 - 27


The fetus begin to develop teeth, spine and limbs. Size is 14 - 20 mm.

 Day 28


The ideal period for ultrasound diagnosis of pregnancy because the embryos are walnut size and it is easy to count them.
There is ossification of the jaw and the skull of the fetus. The shape of the fetus changes originally from ovoid shape to spherical. Size is about 17 - 25 mm.

Day 29


Above is a typical 29 day ultrasound scan - this one was a singleton puppy
The reason I always recommend an ultrasound to give an estimation on numbers, singleton puppy's have a lot against them.
They grow larger, like a fish that grows to the size of its bowl, and become harder for the bitch to get out.
Sometimes one puppy is not enough to provide the hormones to make the dam go into natural labour.
Forewarned is forearmed, know what you are dealing with, and if you have a singleton pregnancy,
discuss options with your vet.

Your bitch may become greedy at this stage, you may want to start to increase food rations, but don't overfeed, excessive weight gain should be avoided.

Day 30
Below is an image of the uterine horns at 30 days gestation with 10 embryos

Complete ossification of the jaw and skull. Size of the embryo is about 2 - 3cm.

Day 31
The growth of sensory hairs on the chin, eyebrows and nose.

Day 32
In mid-gestation embryo reaches approximately 20% of its size at birth.

Day 33
There is a growth of fingers, the ossification of the nose, ribs and leg bones.
Completion of the development of all major organs. Size of about 27 - 30mm.

Day 34

Above 34 day scan clearly showing fetal sacs
Female starts to change behaviour, she may be quieter and more sensitive.
Her abdomen and external genitalia begin to slightly increase.
It is around this time up to 39 days that fetus can be re absorbed.

   Day 35
Below - a 35 day scan performed on a bitch who was referred to the vet
she had a very nasty uterus infection (pyometra), which could have been fatal if not treated

The above ultrasound image shows crystals in the bitch's bladder
There are many types of bladder stones, and each tends to form in a specific breed or species under specific conditions.
85% of patients with struvite bladder stones are female.
Breeds felt to have an increased risk for the formation of struvite stones are the Miniature Schnauzer, Shih Tzu, Yorkshire terrier, Labrador retriever, and Dachshund.
The average age of patients with struvite bladder stones is 2.9 years.


Fetus will have developed all major organs. Size average around 35mm.
Female starts to have an increased appetite and you can increase the amount by 10%.
Rations should be divided into 2 to 3 times a day.

Day 36
Ends period of slow growth of body of the fetus. The fetus start rapidly grow.
It starts with developing reproductive system, continues skeletal ossification and scapula.

Day 37
Begins stage the fastest growth of the fetus.

Day 38
The uterus starts to expand and you will see an increase in volume in the area of the last ribs. You may also detect a slight enlargement of the mammary glands.

Day 39
Growth of fetus is accelerated, skeletal ossification continues.

 Day 40
On the head of the fetus begin to appear the first signs of hair. Eyes are closed. The size of about 65 - 70mm.

Day 41-43
The fetus is about 30% of its total size at birth. Ossification of the spine and fingers.

Day 44
. It's very easy now to feel the puppies, counting them might be a bit more difficult. It is recommended to feed
3 to 5 times a day in smaller doses and increase the total amount of 15-20%. In this period we can not let the female do strenuous movements or jumping.

Day 45 - 47

Above 46 day scan - singleton puppy
Ossification of pelvis and fetuses grow coat.

  Day 48
The female starts to be visibly larger. At this stage, female may lose her appetite.
Fetuses pushes the internal organs of female, most in the digestive tract.

Day 49
Your bitch will begin shedding the hair on her belly in preparation for the birth- this is totally normal and no cause for alarm!
The puppies will continue to grow and develop, and now look almost completely fully formed.
Towards the end of the seventh week, do not add any additional calcium rich foods to the diet.
Dietary supplements, milk, vitamins and minerals are generally not recommended if a high-quality growth/lactation diet is fed.
Feeding excessive amounts of calcium or vitamin D can cause calcification of the soft tissues of the fetus, as well as other birth defects.
Although lactation requires large amounts of calcium, supplementation during pregnancy does not prevent calcium depletion during lactation (eclampsia)
and may actually compound the problem.
Fetuses reach 75% of the size at birth.

Day 50 - 53
Organs are already well developed. Belly is crowded with puppies and you may see sporadic movement.
The bitch may lose her appetitie, but you should feed regularly in small portions. The total daily feed should be increased by 50%.

Day 54
The bitch will spend a lot of time resting preparing for birth as the last of the internal organs develop.

Day 55
The body of the fetus is covered with coat, but the coat on the feet is even less visible.
Claws are already developed. Starts pigmentation of skin. Size of fetus is 145 mm.

Day 56
Starts calcification of teeth.

Day 57
Movements of fetuses are more pronounced. Significantly swollen mammary glands.

Day 58
The fetus has developed lungs and from this stage the fetus is viable if born.

Day 59
The abdomen of the bitch will become loose, uterus decreases and body of female is preparing for birth.
It is time to be prepared, and to have everything at hand.
The female may start to give birth any day now.
You need to start measuring and recording body temperature in the rectum of the female each morning and evening.

Day 60 - 65
. The birth can to occur between the 59th to 67th day. Shortly before birth (12-24h) most bitches refuse to eat normally

and there is a decrease in body temperature from 38-39 °C to 36.5-37.5 °C. (1-2 °C)
Previous hormonal changes lead to the induce of uterine contractions, which subsequently causes abdominal contractions (contractions),
and starts gradually exclusion of fetus. The progress of the delivery can be for each female very different.

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