When to pick the puppy up
Generally, we are so eager to get a puppy that we make the mistake of "the sooner, the better". If we purchase our puppy at a specialized centre, this mistake might not happen, since the puppies sold there are usually 40 days old. This is also true if we adopt one from a dog pound.
However, if we get it from a family or a kennel, this might not be the case. It is better if a puppy learns to feed next to its mother and that the step between milk to solid food (or semi-moist) happens during this time (next to its mother). A puppy needs to be at least 40 days old or eating on its own.
During this time, it has been fed by its mother (breastfeeding) which is an important source of antibodies against several diseases. For this reason, it is important for a female dog to be vaccinated before breeding.
If for some reason we get our puppy before this time, there is no problem if we know what to do. Puppies whose mother died in labour have had their previous owners take care of them from the moment they were born. We will see more of these aspects when we talk about reproduction, labour and newborns.
Conclusion: it is better to get a puppy when its 40 days old, but more importantly, we need to know its needs depending on its age.