command

1:At what age do i have to crop my Doberman's ears? He is 4 months already. 2: How can i teach my dog to sit from down? he gets confuse with the down and sit command. 3: Sometimes in the house he starts to run like crazy, how can i calm him down? Thanks.

Hello everybody, Looking for some advice. I have a 15 month old Male Dobbie. He is a great dog and listens to every command while we are inside. When we are outside its a whole different story. When I call for him to "come" he will run up to me but remain just far enough away that I can not...