The biggest of the litter

This is exactly why it’s recommended to visit the breeder beforehand to see how they operate.

You’ll start to notice it yourself after chatting with owners of both brilliant dogs and those with behavioural issues. I always ask what age the pup was when they left their mum and how the breeder raises them; you’ll form your own opinion over the years. It’s the same when you talk to enthusiasts of a specific breed. A couple of years ago, I spoke to a lady who knew the reputation of every Corgi breeder. She’d tell you, "Go to her, definitely—she does a brilliant job with the pups and they turn out to be lovely dogs. But avoid that person; their dogs look stunning, but they’re a nightmare to live with."

Because, once again, it’s gradually becoming the norm. So, I don’t really know.

Look, I'll put it this way:

If the breeder does a good job (I start caring less about the littermates between the 8th and 10th week) regarding socialisation, as is the case for some, then yeah, 10-12 weeks. If the breeder neglects this aspect, I’d rather get the puppy out of there at 8 weeks and take care of it myself. The window is so short that I have to admit, losing a whole month isn't ideal.

I was lucky enough to have a breeder who really put the effort in. She was socialised with farm animals, other dogs of course (her littermates), cats too, and loads of people.

As for her littermates, well, she’s never seen as many dogs as she has since her first day with me. She only had one brother and one sister, so she’d seen all there was to see there. At the park I go to, she met at least 50 dogs in the first week. Now that’s more like it.

So no, I’m not quite so black and white about it. But I definitely see the yellow flag here, and especially the red flag for any adoption before 8 weeks.

The biggest or the smallest—it really doesn't mean anything at that age, neither for their future size nor their temperament. It’s likely just that the breeder was putting out a single bowl for several of them, so it was down to whoever was the quickest or most resourceful to get the most food. When I first went to see my Jack Russell, I had to choose between four 3-week-old puppies, and they were all pretty much the same size. In the end, my girl chose me; she was the one following me around, climbing onto my lap and growling if the other three tried to get near. The breeder wouldn't let me come back until the pups were at least three months old to ensure proper training and socialisation. When I did return, my Jack and her brother were average-sized while the other two were "chunkier". But that doesn't mean a thing because my Jack is a perfectly normal size for the breed now; she doesn't have to fight for her bowl anymore and she’s developed a very strong personality! ;-)

So, once your pup is home, their appetite will regulate because you’ll be giving them high-quality dry food, in the right amounts, at set times.

I actually agree with @Energiesolaire and @Humeur de chien, 8 weeks is too early. Breeders often do it under pressure from people who think the puppies are cute and want to take them home straight away; the breeder then worries they’ll change their minds, and it saves them money if the little ones leave sooner.

The advice is usually to adopt at 3 months, or 12 weeks—there’s a massive difference compared to 2 months.

My pup was very well-socialised; we even travelled home by train and the Tube—3 hours in the noise and crowds—and she didn’t bat an eyelid, showing no fear of other dogs or people. But whether they are socialised or not, you are responsible for their training and development from A to Z for at least a year. It’ll take months for them to be house-trained, months to learn to stay home alone, months to learn not to nip fingers or clothes when playing, months to see their personality and behaviour develop alongside humans and other dogs, months for recall, etc. etc.

In short, big or small, it says nothing about their future adult size or their character. Once they’re home with you, they’ll grow and develop based on the training, love and patience you give them.

They pretty much all do that nowadays. Around here, puppies all head to their new homes at 8 weeks. To be fair though, I have to give them credit, some do a massive amount of socialisation work between 4 and 8 weeks. It won't stop the puppy from nipping a bit too hard when playing, but at least they’re well desensitised to loads of things; they're fine with humans, cats aren’t too tricky, and they get on well with other dogs.

But that’s just the way it’s gone.

I know a massive Australian Shepherd. He’s different, lovely. More like a Golden Retriever x Husky cross in his attitude. Very primitive, confident, really calm and laid-back. Very, very playful and brilliant with other dogs.

A puppy's size at this age isn't actually a reliable way to predict their adult size.

And as for their temperament, I personally prefer having the biggest of the litter rather than the runt.