I think I owe an apology to NYC police officers. In my posting about Lisa Ludwigson and her leashed dog being attacked by an unleashed dog I inferred that the local precinct wasn't doing their job. I have since done some research and posted a question on a police officer discussion forum. Ms. Ludwigson was, in fact, given the correct information:
1 - In almost all cases if a dog bites a dog it is a civil matter.
2 - "Summonsable offenses are only enforceable if occuring in the presence of an officer, and also affect by discretion."
If, when the police arrived, the dog was under the control of its owner, they could not give him a ticket. For all intents and purposes, legal systems consider dogs as property. If you have a witness and the dog owner's name & address I recommend suing him in civil court.
How to file a civil lawsuit