When puppies are born, owners are often eager to welcome these new additions to their families. It might be tempting to assimilate them into their new human family immediately, or to pass them on to new loving homes. However, the most important thing in this crucial time of puppies’ lives is to be with their mother and new brothers and sisters. If the proper timeline isn’t followed, the puppies could develop problems later in life, and the mother can experience medical problems.
Taking a puppy away from its mother in the transitional stage 2 - 4 weeks can create a number of problems for later life. Any time before 8 weeks even, can cause problems – so that a puppy is pre-disposed to become fearful of other dogs. Ideally the whole litter should be kept together until at least 8 Weeks.
Puppies removed from the litter too early are prone to be nervous with a tendency to bark and bite. They are also less likely to accept discipline and may also be aggressive to other dogs. In her own words, ‘’Generally speaking, a puppy taken away from its mother and litter mates before seven weeks of age, may not realise its full potential as a dog and a companion. To maximize the mental and psychological development of puppies, they must remain in the nest for 8 weeks.
Releasing a puppy too early has no benefits for the puppy and can cause a host of sometimes irreversible emotional and behaviour problems in dogs. This practice will only serve to harm your dog and make your job as the owner of this dog unnecessarily difficult.
After your puppy has reached the appropriate age, you will become his ‘parent.’ If the canine mother is no longer in the home, it is natural for a puppy to cry or whine at first as he adjusts.
Puppies can also become too clingy to their new humans and have serious issues of separation anxiety when removed from their mothers during the transitional period.
When the puppy is first separated from his mum, he will need a lot of attention and contact from you. Let your puppy sleep in a crate next to your bed until he adjusts to his new surroundings. This will reassure the puppy that he has not been abandoned, and it will help the bond between you grow stronger.
Puppies begin to be weaned off their mother’s milk around three to six weeks of age and are typically fully weaned between six to eight weeks of age. By the time you get your new puppy home, it will have been eating puppy food. If you do decide to a few weeks. The breeder or adopter will provide you with information about the type of food being fed. It’s best to start with the same diet whenever possible. Allow your new puppy to adjust to its environment for a few days or weeks before you choose a new food for it.
Having said this, we must also consider how taking a puppy away right in the middle of its ‘sensitive period for socialisation’ can also cause issues and this is why it is essential that breeders start to 
understand the important role they have in bringing up the puppies. Breeders who understand the socialisation and critical periods can make the difference between a new owner having an amazing dog and one that is going to be difficult for them. It will also make the breeder much more successful and ‘desired’ if they can send puppies into the world that make fabulous dogs.
And sadly, dogs that have been removed from their family unit before they are 8 weeks old, these socially immature dogs go on to be the dogs that are involved in most of the social skirmishes at the dog park, at doggy day care, etc., and in one-on-one chance dog encounters. These poor dogs don’t stand a chance in social situations because they are clueless about what appropriate and polite social dog behaviour should look like. They never had a chance to see it modeled by their mother or their siblings and they never had a chance to practice modelling these behaviour’s themselves.
To help you to understand the gravity of this situation, relate it as if we were speaking about a 3-year-old child. Removing a puppy too soon from their family unit is the doggy equivalent of taking a 3-year-old child and sending him off to boarding school and expecting him to be able to cope emotionally and socially with the experience.