Dogs go through a few different sensitive periods during their lifetime, when it comes to their physical and behavioral development. Some of these periods are quite important, due to the impact they’ll have on the dog’s personality and behavioral health. We can identify nine different phases; in this article, we’ll discuss some of the particularities of each of them. Phase One The first phase is the fetal period. This includes the development of the fetus up to parturition. During this period, the puppy will be influenced by the mother’s experiences. If she’s exposed to high levels of stress, the puppies will be prone to develop anxiety and fear. It is also during the fetal period that the male’s brains will go through a masculinization process, due to the production of testosterone. This will make them more likely to exhibit typical male behaviors such as urine marking, roaming, inter-male aggression and...