further to development and critical periods for socialization --- it is during the age of your dog when trust is established . It is a tricky age because you do want to give some discipline , little pressures so that the dog builds in tolerance , but if too harsh, too much , too demanding then you can easily confuse the dog and come to mistrust humans , not because "they" have made the impact , but you , the representative have . You have to be fair and firm . If you go with the idea of 'oh its still a baby' and allow the dog free rein to do what he pleases then you have a dog that won't be as responsive or as resilient , because changes in behaviour which could have been done with praise for the right response will need more effort on your part later on. This is the period for learning trust and gaining confidence , not exposing the dog to harm , over tiring , over stimulating , but making learning and doing the right thing rewarding , not emphasing the negative aspect or the correction . So instead of hovering over the dog with a no no no , leave it (negative) , CALL him to you , make it so rewarding , nothing negative involved. You have killed two birds with one stone - he leaves the cats food which was the desired response and you have built a great recall and positive association with your self. Reward amply.
Personally I love this age .