Video: Development Of A Puppy From A Single-celled Embryo To An Adult Dog
Transitional period (13-20 days). The transition period lasts from 13 to 20 days of the puppy's life. During this time, important physical changes take place in the development of the puppy. At the beginning of this period, about the 13th day of life, his eyes open. His pupils are already responding to light, but the retina of the eye is not yet developed, so he cannot see objects and their movement until about 21 days of age.
The puppy begins to crawl backward as well as forward, and a few days later he will begin to walk with an unsteady gait, swaying from side to side and falling frequently. Once standing on its paws and starting to walk, the puppy practically stops crawling. The first teeth erupt at about day 20 and he begins to bite and chew. At the same time, he begins to wag his tail, although he still sees and hears almost nothing. He begins to react with a startle to harsh sounds at about 19.5 days of age, but he cannot yet determine where the sound is coming from.
Thus, during this critical period, rapid physical changes occur in the puppy's body. In just one week, from a helpless creature that cannot hear, walk, empty its intestines without assistance, maintain its body temperature, and can only suck milk from its mother, it turns into a puppy that can do all this.
Cognitive period (21-28 days). The cognitive period lasts from 21 to 28 days of life. This is the first week in which the puppy begins to use his sight and hearing. These changes in his perception occur very abruptly, within 24 hours in most puppies, so at this time he needs a stable self, a stable environment. Now he most needs the presence of his mother and familiar surroundings.
If at this time the puppies are taken away from the mother or transferred to a new place, this will affect their further physiological development.
During the cognitive period, the puppy begins to learn. This is a time in a puppy's life when he learns what it means and how it is to be a dog.
Socialization period among dogs (21-49 days). Socialization is the formation of a complex of social behavior. The period from 21 to 49 days (or from 3 to 7 weeks) is the period of socialization of the puppy among the dogs, when he learns to use species-specific behavior that allows him to communicate with other dogs. For all the signs inherent in its genes to develop, the puppy must remain in the nest with its mother and littermates all this time. He perceives the appearance of a person and his own kind, that is, of his breed. That is why, when a dog grows up, it usually prefers to communicate with representatives of its breed.
During this period, he will learn to use special body postures, facial expressions and sounds to communicate with fellows, and understand the impact they have on littermates, the mother and other dogs with whom he contacts. He learns a variety of dog behaviors.
In the game, he learns the world around him: hunting games, imitating the pursuit and attack on prey, teach him the consistency and coordination of movements; he learns the ritual of greeting when meeting dogs; wrestling games teach him how to use his body, posture and facial expressions to evoke different reactions from his fellows. For example, if the playing puppies have a conflict, the puppy learns that the submissive posture prevents aggression. In games, puppies often make cages on each other, deprived of such games, a male who grew up in isolation has difficulty learning to mate, and may even not even pay attention to bitches in heat.