Canine Manners 101: Hurry Up!
Teaching your dog to "do his business" on command is one of the most useful word associations you can teach him - especially when it is pouring rain or when there are inches of snow on the ground and you have your slippers on. This process is a very simple one and most dogs will easily pick it up. You can start working on this with your puppy as soon as you come home and even older dogs can learn this readily. “Old dogs can’t learn new tricks” does not apply here!
The concept: Positively reinforce your dog's association between the command and the act of going to the bathroom.
Step 1: When your dog is starting to urinate or defecate calmly say "hurry up" (or whatever command you'd like to use- however don't make it too embarrassing, remember - you do have to say it in public!).
Step 2:When your dog is done going to the bathroom, praise him and give him a treat.
Make sure you give the command as he is going, and do not sound overly excited or you might distract him from his "calling" and he’ll stop. Soon your dog will learn to associate the act of going to the bathroom with the command and you will be able to ask him to "hurry up" when you are running late for work and you need him to go right away.
Please remember that this is not something that you can force so if your dog doesn't go when you give the command it's not appropriate to scold him in any way.
Canine Manners 101 Training Series