This is important information.  It is not uncommon for some puppies to urinate when they are excited or scared.  They are not aware that they are doing it.  It is important that you do not scold them for this.  You have to just ignore the fact that it happened.  Don’t get excited or show stress about the accident.  If you scold the puppy, you will only make the matter worse.  The puppy will anticipate being scolded and therefore be more likely to urinate in those situations.  Be patient.  This problem is most common in female puppies under 1 year of age and the puppy will eventually outgrow the problem.

Situations that precipitate submissive urination include: over affectionate greetings, guests entering your home, arguments between people, scolding and loud noises.

Dogs are social animals that use subtle cues to maintain order and prevent disputes. In order to display deference to a more dominant individual, a submissive dog uses gestures such as averting her eyes, rolling on her back, and urinating. So when a dog feels intimidated or threatened, the appropriate response is to offer a submissive signal. These signals demonstrate that the dog recognizes another individual's dominance. The urination that occurs is not a spiteful act but a natural part of a dog’s behavioral repertoire. If the problem occurs when friends greet her ask them to do this, too.  Submissive urinating often occurs when a dog encounters another animal or person that they consider dominant. 

Excitement urination
Usually occurs when puppies have not yet developed proper bladder control. They may urinate every time they feel excited, most of the time without even noticing. When this happens, do not get upset or reprimand your puppy for urinating. If you do, then the problem can turn even worse because it will turn into submissive urination. To prevent this from happening, you should increase your puppy's exposure to the event that makes him urinate. Do this, as many times as possible in order to make it so common that it no longer excites your dog. As your puppy grows older or simply loses interest in the event, the problem will be eliminated. Sometimes puppies urinate because they are excited to see people that come to the house. If this is the case, have the people come in and get sat down before the puppy sees them.  Then take the puppy outside to potty before they see guests.  Tell guests to ignore the puppy for a while when it first comes in until the puppy settles down.  Then the guests can give the puppy attention but don’t have them make a big fuss over the puppy.