Ontogeny is a technical term from biology and describes the development of an organism from the fertilized egg to the adult being. Accordingly, this development applies to humans as well as animals, although the original theory by Ernst Haeckel (1834-1919) is very controversial. Instead, various development phases have remained from the ontogeny of dogs and cats. Here, dogs, cats, etc. are divided into different phases from birth to adulthood. These phases differ greatly even within the individual dog and cat breeds. For example, the first phase of life of a Border Collie is around seven days, while the same phase is estimated to be around 19 days for the Labrador Retriever. Furthermore, the four development phases in dogs and cats should logically be considered separately in time, although cat development is practically identical in the first phases.
In the 1st and 2nd week, a puppy or kitten can be seen that is practically disorientated and instinctively seeks proximity to its mother. This is followed by a short transition phase before the animals become increasingly accustomed to their surroundings and unfamiliar creatures in the socialization phase. This is where the greatest differences in time occur, because this development phase lasts between four weeks and three months for dogs alone. In the final hierarchy phase, the animals find their place in the pack. This falls during adolescence and occasionally causes trouble between animals and humans, because dogs and cats practically restart their development in this phase, refuse to follow learned commands and simply test their limits. Once they have all gotten used to each other again, the ontogenesis from birth to adulthood is complete.
