Why would any one keep any dog in a cage all day. Now puppies need to be caged when your not home or sleeping, they chew and can chew cords that cause fire. Let them out when your home and time for bed put them in their cage it will be their own private dog house later on. It will not become aggressive, you take it out, feed it play with it and it lays down while you watch TV. 8 hours of bed time is acceptable, and when you work. The rest of the time is OUT OF THE CAGE. Make you dog happy and everything is fine.
It depends on how much it loves you:)
It wont become aggressive but it could endup suffering from depression because it ia always by them selfs and that could lead to sickness and when you do let them out they will not know how to act with people or they could even be reallly hyper. If it is a puppy and not house broke I would put the puppy in there overnite just until house broke and if you leave the house until the puppy can be trusted not to get into anything but besides that there is no reason your dog should be in a pin.
Yes most defintly!! Not to you but to people n other dogs. N then again it matters on how good you treat your dog.