Let's say you own a dog, and one day you are walking down the street just like any other day. It's your normal "walk" route for you and your dog. Suddenly, a suspicious-looking person approaches, and you become convinced the person is a threat. You sick your dog on the person, who is bitten and suffers a minor injury.
A nearby police officer saw the entire incident and comes over to talk to you about it. The officer determines you were at fault; but instead of being hit with a fine, you are arrested and charged with a weapons-related crime. Yes, that's right -- your dog is being classified as a weapon.
As recently as a few years ago, this would be an exception to the rule. Dogs were not classified as weapons, even though there were many attempts to do exactly that. However, the courts have recently altered their thinking about dogs and the way they are used in violent situations. That change in thinking has resulted in more people being charged with weapons crimes when their dog attacks.
Now, there may be some very legitimate weapons charges being filed against a person in some cases where a dog attacked. But even in those cases (and especially in the cases where the charges are questionable), the accused person should vehemently defend the charges. Classifying a dog as a weapon could be a situation where the police and prosecutors are just trying to tack extra penalties and consequences to a person's possible sentence.
Source: New York Times, "Instruments of Danger in Weapons Case Were Dogs, Authorities Say," J. David Goodman, Oct. 6, 2013