The gestation period for dogs is only around 9 weeks, but in that time the most incredible transformation occurs. And that’s before it even takes its first breath as a newborn puppy.
* First day of mating.
* Sperm travel searching for a mature ripened eggs.
Fertilization to 7 days
* Fertilization occurs.
* 2 cell embryos are in the oviduct.
* Cell division occurs 12 hours after fertilization.
* The embryo is fairly resistant to external interference in development.
* Embryo will be 4 celled at start of week and 64 celled by end of week (size of a poppy seed).
* Around day 10 embryo becomes 16-32 celled (now called a morula).
* Also around day 10 a 32-64 celled morula enters uterine horn.
* Day 11 a fluid-filled inner cavity forms in the morula (now called a blastocyst)
Days 15 - 21
* Day 19 implantation occurs in uterus (size of a sesame seed).
* During the next two weeks the important organs will develop.
* The embryo is sensitive to external interference in development
* Her nipples begin to turn pink and enlarge.
* May loose appetite during this week.
* Morning sickness may occur.
Days 22 - 28
* Fetuses grow from 5-10 mm in length to 14-15 mm long (size of a pea to blueberry)
* Morning sickness should go away and appetite return.
* One of the early signs of pregnancy is for the dam to 'adopt' a toy.
* Development of eyes and spinal cord and faces take shape.
* The fur on the belly and around the nipples thins.
* Organogenesis begins Embryos are highly susceptible to defects and external interference
* Day 25 ultrasound can be performed to visually see puppies and confirm pregnancy
* Days 26 to 32 puppies can be palpated this is the best time to palpate because the fluid amount increases after and it will be harder to palpate (this is something that should only be performed by those who have been trained)
Days 29 - 35
* Fetuses grow from 18 mm to 30 mm in length (size of a grape to a green olive)
* Diagnosis by x-rays is usually possible after 55 days (95% accuracy for determining the number of puppies).
* You may be able to feel the little puppies -they would be the small bumps in the abdomen.
* Development of toes, whisker buds, umbilical cord, and claws. Eyes now close.
Day 30-32 Organogenesis ends . Embryos are fairly resistant to interference Now called a fetus and resemble a puppy. Around day 33 gender can be determined She may be showing... She may also gain a little weight particularly if she is going to birth more than 1-2 puppies..
Days 36 - 42
* During the last several weeks, your dog's nutritional needs nearly double. Feed small meals several times a day.
* Fetuses weigh around 6 grams and are 45 mm long (size of a small fig)
* Skin pigmentation visible.
* Fetal heartbeats can be heard with a stethoscope
* Day 40 to 42 ossification of the bones begin
* Enlargement of mammary glands as nipples darken and enlarge.
Days 43 - 49
* Further growth and development continues. Puppy Kicking can distinctly be felt towards the end of this week.
* She may shred papers, blankets or bedding in an attempt at "nest building" in the last weeks.
* During the last 2 weeks, your girl may become irritable and should avoid contact with small children.
* Moderate exercise is the proper approach. Neither forced rest nor strenuous exercise is a good idea. Short periods of gentle play and short walks are good..
* You may feel the puppies now but counting them may be a bit more difficult.
* Definite abdominal enlargement.
* Abdomen hair will start shedding.
Days 50 - 57
* Puppies are now viable and can safely be born from about day 56
* Fetal count can be accurately measured via x-ray.
* Dam begins to spend a lot more time grooming herself.
* Her breasts become swollen as her milk forms.
* Nesting begins as she looks for a place to have her puppies... Make sure you have her box or spot ready..
* The dam may not have as big of an appetite during this period. Her abdomen can be crowded with puppies.
* You can feel the puppies move now.
* See if you can get her used to her whelping box
* Nipples and vulva should be gently cleaned with warm water, you might want to trim the hairs surrounding the nipples, to allow easier access for the puppies to suck.
* She may express milk from her nipples.
* Watch for her temperature to drop. You may take it rectally if you want but she's just plain old cool to the touch compared to what she has been the last 8 weeks.
* She may also become restless, seek seclusion and in the last few days, soil the house.
* She will be 'nesting' 12-24 hours before the birth