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)
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.
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.
The bitch and male are ready for a second mating
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.
During the second week of pregnancy, the cells which will develop into your puppies begin to grow and separate,
and the tiny new embryos descend into the uterus for the remainder of the period of gestation. Your dog should still be fed and exercised normally during this time.
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.
The embryo migrates in the womb and individual embryos are diffused in uterine corners where later the nesting into the uterine wall begins.
They will receive the vital nutrients and life support which the bitch’s body provides during their time in the womb. The foetuses are under a centimetre long at this stage.
Continue to feed and exercise normally, but begin to monitor your bitch for increased appetite and provide for her developing needs accordingly.
Do not make any sudden or unnecessary changes to the content of her diet.
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.
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
Embryos are nesting and the nervous system begins to develop, followed by the head and body.
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.
A very early scan on my own bitch, 19 days from ovulation
Development of the internal organs
You may notice a slight discharge from your bitch at this stage which comes from around the placenta.
The placenta is formed, the fetus is around 5 – 8mm
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
The fetus starts to develop eyes, ears, nose, jaw and liver.
Above a clients bitch I scanned early as per request due to previous pregnancy problems – scan on left at 23 days and right 7 days later at 30 days gestation
. The eyes and spine of the foetuses begin to develop, and their faces begin to take shape. The foetuses grow to around 1.5 centimetres long during week four. Your bitch’s teats may begin to swell at this stage, and she may have a thin, clear discharge from the vagina.
Due to the rapid development of all major organs, the actual fetal growth is slow.
Another Day 24 ultrasound image
Day 25 – 27
The fetus begin to develop teeth, spine and limbs. Size is 14 – 20 mm.
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.
The fourth week of foetal development is considered to be one of the most formative stages of the pregnancy, when the growing puppies are most vulnerable to damage and developing defects. At this stage of development, begin to limit rough play and particularly strenuous exercise in your dog.
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.
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.
The growth of sensory hairs on the chin, eyebrows and nose.
In mid-gestation embryo reaches approximately 20% of its size at birth.
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.
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.
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.
Begins stage the fastest growth of the fetus.
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.
Growth of fetus is accelerated, skeletal ossification continues.
On the head of the fetus begin to appear the first signs of hair. Eyes are closed. The size of about 65 – 70mm.
The embryo is now about 30% of its total size at birth. Ossification of the spine and fingers.
Foetuses develop their sex organs at the start of week five. Finally, they look like little puppies.
If an ultrasound is done, you can easily see leg buds and toes, but don’t expect to know whether they are boys or girls.
. 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.
They will now start to grow fur, and as puppies continue to grow, the next step is pigmentation. Then, they form eyelids.
Day 45 – 47
Above 46 day scan – singleton puppy
Ossification of pelvis and embryo grows a covering of fur.
The female starts to be visibly larger. At this stage, female may lose her appetite.
Embryo pushes the internal organs of female, most in the digestive tract.
Now the puppies are well developed and begin to reach the necessary size for birth.
If you were still wondering when you’ll be able to feel puppies move in a pregnant dog, now is the time.
If you are patient, you can even see the puppies’ movement in your dog’s abdomen.
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 embryos 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 embryo, 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%.
The bitch will spend a lot of time resting preparing for birth as the last of the internal organs develop.
The body of the embryo is covered with fur, but the fur on the feet is less visible.
Claws are already developed. Starts pigmentation of skin. Size of fetus is 145 mm.
Starts calcification of teeth.
Movements of embryos are more pronounced. Significantly swollen mammary glands.
The puppies have developed lungs and from this stage the puppy is viable if born.
Avoid any rough and tumble play or stimulation which might lead to the onset of early labour, as ideally your pups should spend another week in the womb.
Your bitch will probably begin ‘nesting’ at this stage, and you may even be able to see and feel the puppies moving within her tummy when she’s lying down.
Towards the end of week eight, your bitch will start producing colostrum, the forerunner to her nutrient- rich milk, and then the milk itself.
Continue to feed as much as your bitch will eat and prepare for the birth!
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
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.
After the birth
Make sure each puppy gets some of the bitch’s colostrum (first milk) within first 24 hours.
Vaginal discharge should be reddish to reddish-brown (green is okay on first day). If you see black discharge, contact your vet asap.
Within 5-6 hours of last puppy’s birth, you can have an ultrasound to ensure the bitch asn’t any retained puppies or placentas.
You should also check each puppy for cleft palates as they may not survive unless they are tube fed.
Mastering Abdominal Ultrasound in Dogs and Cats – Reproductive Tract