A puppy’s journey: from a single cell to a 12-week-old puppy

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The gestation period for dogs is only around 9 weeks, but in that time the most incredible transformation occurs. Witness the remarkable metamorphosis as puppies develop inside their mother’s womb, then continue to rapidly evolve in the weeks after they’re born. This is the complete journey of a puppy - as you’ve never seen it before!


Week 1-2: from cell to fetus

Woohoo! Today my egg is fertilized in the fallopian tube and I can start my big journey. I leave for the womb along with my future brothers and sisters. We distribute ourselves nicely, so that no one is alone, and nestle up tight in the soft uterine wall. I divide from 4 to 64 cells and immediately get a head and spine!

Week 3-4: as big as a hazelnut!

By the 19th day, I hide even better within the uterine wall. Unfortunately, this can make my mom feel a bit sick, but it won’t last too long.

In week four, my head grows, and I get eyes and my first vertebrae. I am now growing very fast and I have almost tripled in size. Did you know that I am already about 15mm? That's as big as a hazelnut! I also get my organs. If Mom’s owners want to see us for the first time, the veterinarian can now locate us with his ultrasound.

Week 5-6: I’m a boy!

I look more and more like a real puppy, with teeth, toes, nails and whiskers. My organs are already complete, and I get my skin colour. Mom is finding it a bit difficult, because she has become much heavier and we are very active down here in our little swimming pool. Most excitingly, we are now becoming a boy or a girl. And guess what? I’m a boy!

I was lucky to get a good spot in the womb. Because I am close to the blood supply, where the most food comes, I am now the strongest in the group. After week six I weigh about 6 grams and I am 45mm.

Week 7-9: Preparing for the outside world

Mom’s owners can see me very clearly with the ultrasound at the veterinarian, because my skeleton is now complete. They can also feel me when I try to give a little kick. Mom is almost bald on her stomach so I can easily find a place to nurse when I’m born. These last few weeks are pretty hard for Mom, but I'm almost there!

I put all my energy into growing, growing and growing some more. Eating becomes more difficult for Mom, because we take up so much space, so her veterinarian recommends that Mom eats a higher calorie diet. From day 57 (beginning of week nine) I can safely come out, although I’ll usually wait until 60 to 63 days.

I cannot wait to get out there and play!


Newborn to 2 weeks: Sleep and grow!

Well, hello world! Except, I can’t see anything yet. Or hear. My siblings and I are all blind, deaf and toothless for the first week or two. We also can’t regulate our own body temperature yet. My siblings and I depend on Mom and each other for warmth, and we huddle together in a big cozy pile.

It’s been a busy few weeks of growing, so I spend 90 percent of my time sleeping! All the energy I do have is used for growing, and my weight has already doubled in the first ten days.

I can’t support my own weight yet, but I can just about crawl about using my front legs.

Week 2 to 4: I can see! And hear! And walk! And talk!

There have been lots of changes in my second week of life. My ears and eyes have both opened, giving me a whole new sense of the world around me. Mom looks as lovely as I knew she would and so do all my little fluffy brothers and sisters. We are all starting to chat a bit more now with little yelps, whines and barks. Oh, and - very exciting - by week three, I took my first wobbly walk!

This is a time of rapid physical and sensory development for us puppies. We are starting to play with each other, and we even cheekily try to take food from Mom’s bowl. I’m starting to control my toilet needs a bit better and I’m moving away from where we sleep when I need to go.

Week 4 to 12: Time to get social!

I’m told that week three to about week ten is an important socialization period. That’s the time I will form attachments that I will remember the rest of my life!

Mom’s milk started to slow down at around four weeks, so now I’m starting to eat solid food. By the time I am six weeks old all my baby teeth will be in, which really helps me eat lots more solids.

At weeks six to eight, I am at a really important period to learn to accept others as a part of my family. By the time I am ten weeks old (they say this happens to all puppies from about week eight to twelve), I find I am a little scared of meeting new people. I appreciate it when my owners are very careful with my socialization during this period.

Staying with my brothers and sisters and my Mom at this stage is helping me learn all sorts of useful things: bite inhibition, how to understand and react to normal canine communication, and my place in doggy society.

Now that I am a twelve-week-old puppy I am finally ready to meet my owners and move into a cozy house of my own. Yay! How exciting!

I just met my new forever family and, wow, I already love them sooo much! Now I’m just waiting for them to think of a good dog name for me. Animal experts have proven that some dog names may be better than others. I hope my new owners do some research on how to name your new dog. No matter my new name is, though, I just know it will be perfect, because my new owners will have chosen it with love!

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