Someone of the list asked for this information regarding biting.
Classifications of Bites
Well-known veterinarian, dog trainer, and behaviorist Ian Dunbar has developed a six-level system of classifying bites, in order to make discussions of biting behavior more consistent and understandable. Those levels are:
Level 1 Bite - Harassment but no skin contact. This is the
so-called snap. Don?t kid yourself. A snap is an intended
air bite from a dog who did not intend to connect. He
didn't just miss. It is a lovely warning signal, telling us that
we need to identify his stressors and either desensitize
him or manage his behavior to avoid exposing him to the
things that cause him undue stress.
Level 2 Bite - Tooth contact on skin but no puncture. Again,
this is a bite from a dog who didn?t intend to break skin,
and a warning that this dog is serious. It?s a very good idea
to remove the dog's stressors at this point, before he graduates
to the next level.
Level 3 Bite - Skin punctures, one to four holes from a
single bite (all punctures shallower than the length of the
canine tooth).
Level 4 Bite - One to four holes, deep black bruising with
punctures deeper than the length of the canine (which means
the dog bit and clamped down) or slashes in both directions
from the puncture (the dog bit and shook his head).
Level 5 Bite - Multiple-bite attack with deep punctures,
or multiple attack incident.
Level 6 Bite - Killed victim and/or consumed flesh.