Pregnancy Time Table

Human embryo in early developmental stage.

This section applies to Jack Russells and all puppies/breeds for that matter. It goes over the growth of the puppies while in the womb.

X-ray of a pregnant animal with fetuses.

This is an X-ray of Goose's pups at about 50 days pregnant. You should be able to count 7 spines and 7 skulls.

Medical ultrasound image showing internal structures.

This is a sonogram of Bitsy's pups. You can see 5 circles which are 5 different puppies. The one the bottom left is a good view of the pup in its sac. These pups are about 35 days old.

Pregnancy Time Table: Week 1 - 9

Week One

  • Fertilization occurs.
  • 2 cell embryos are in the oviduct.
  • The embryo is fairly resistant to external interference in development.

Week Two (Days 8-14)

  • Embryo will be 4 cell at start of week and 64 cell by end of week
  • Embryo enters the uterus

Week Three (Days 15-21)

  • Day 19 -- Implantation of embryos in uterus.

Week Four (Days 22-28)

  • Development of eyes and spinal cords.
  • Faces take shape.
  • Fetuses grow from 5-10 mm to 14-15 mm.
  • Organogenesis begins - Embryos are at their most susceptible to defects.
  • Days 22-28 are the best days for a sonogram to get a puppy count.
  • Days 26 - 32 are the best days to palpitate (i.e; feel for the puppies ...which is near impossible)

Week Five (Days 29-35)

  • Development of toes, whisker buds, and claws.
  • Fetuses now look like dogs.
  • Gender can be determined.
  • Eyes (previously open) now close.
  • Fetuses grow from 18 mm - 30 mm.
  • Organogenesis ends -- embryos are now fairly resistant to interference with development.

Week Six (Days 36-42)

  • Development of skin pigment.
  • Fetuses should weigh around 6 grams and be 45 mm long.
  • Fetal heartbeats can now be heard with a stethoscope.

Week Seven (Days 43-49)

  • Growth and development continues

Week Eight (Days 50-57)

  • Fetal movement can clearly be detected when Mother-to-be is at rest
  • Puppies can usually be safely born from this point on

Week Nine (Days 58-65)

  • Growth and Development continues

CHANGES IN MOTHER-TO-BE

Nesting behavior may be seen. By now she should have a place to go where she feels safe and away from other dogs, kids and noise. She should have a least 1 week (if not 2) where she has established her place to have her puppies. Appetite may disappear as whelping approaches. Not all, but most will stop eating altogether the day before.

Behind the Cute Photos

Newborn puppies nursing from their mother.

These puppies ^ are just hours old.

Newborn puppy sleeping in a person's hand.

This little Jack Russell puppy ^ is just a few hours old.

White puppy standing on a rock.

Bogey is a well-rounded and wonderful little Jack Russell. He graduated from our Polished Puppy Kindergarten School before heading off to his home in Massachusetts.

Cute puppy with brown and white fur.

This puppy lives on a farm in Texas and travels the road with her musician family.

Children sitting on grass with puppies.

This is Lucy and Hudson. Our little Jack Russell "Helpers". They are Stephanie's children who, of course, live in Maine at Connemara Terriers. 🙂

Brown and white puppy with big eyes.

Penny lives in Massachusetts with two other dogs. One Jack Russell and a French Bulldog. They are all good friends.