After reading the back and forth commenting about "vicious" dogs on this board (and now this thread), I have to put in my 2 cents. Sorry it's a long post!
I am a dog owner and my family had multiple dogs when I was growing up. My mother is a former vet tech and taught me many things about dogs, including training and knowing how to spot the signs of a sick/disturbed animal. We had some interesting dogs growing up, but none of them were ever a danger to me (as a child) or anyone else. We had a "family breed" dog, along with some terriers over the years.
My current dog is a mutt--probably some whippet, greyhound, weimeraner, and (horrors) some pit in him. He is the most gentle, gentlemanly dog I have ever had...because he wasn't allowed to be anything else. I trained him starting IMMEDIATELY when I got him (at 7 weeks old) to be a good dog.
What does that mean? Here's some thoughts:
1.) CRATE TRAINING: I can't believe people think this is cruel. Dogs are "den animals", meaning they feel safe in cave-like places. Buy an appropriate sized crate and pad it with towels until they learn to control their bladder/colon.
Also, NEVER use a crate for cornering your dog so you can hit him. The crate is ALWAYS their safe spot no matter what. You can send them to their crate if they are bad, but they have to know they are safe from any physical harm.
The crate also keeps them safe when you are gone from the house--they can't get into everything (or, when they're young, pee/poop in secret locations).
2.) SCHEDULE/ROUTINE: Have one. Dogs live by it. Wake up, go outside, get breakfast, go into crate while dad's away, get out when dad comes home, play, eat, run, follow dad around house/yard, go to bed in crate. DO NOT get a dog if you can't spend time with him (i.e. you are gone all day & all night) & socialize him with others. A crate-trained dog is wonderful--a crate-BOUND dog (for 18 or more hours a day) is just sad and cruel.
3.) DO NOT ENCOURAGE "CUTE" BEHAVIOR AS A PUPPY YOU WILL HATE WHEN THEY GROW UP: As a puppy, my dog liked to "gnaw" on me. I got in the habit of pinching his nose every time he did it and he stopped in a couple months time (and never chewed anything else either). He now has a very gentle mouth, even with the vet.
Same thing with barking--starting from the time I got him, I always told him NO with a stern look, even though he had the cutest little bark. But I KNEW that not discouraging that behavior then would lead to a lot of problems later, so he was corrected. Now, he barks rarely (when strangers knock at the door and that's OK with me), but NEVER at people I welcome in the house and NEVER when we walk or go socialize at the park.
When I see these (mostly) women with these little yapper dogs they don't correct, I just laugh at them. They thought it was "cute" as a puppy, didn't discipline the dog because "he's just so wittle an' cute"...and now they are stuck for the next 15-20 years with a dog that won't shut up. That's your fault, sister--not the dog's. You are the one who changed the rules about barking!
3A.) DO NOT TEASE YOUR DOG INCESSENTLY: The dog doesn't like it--it is not playing. It is being cruel. If you teased a child like some people tease dogs, they would lock you up for mentally abusing the child. The child can cry as an outlet--the dog internalizes it and becomes mean because that is the only outlet they have (to protect themselves).
Seriously, if you need to prove your superiority as a human being to something, go prove it to another human being. Dogs depend on YOU--YOU are their world. So why are you teasing them until they turn mean? Once again, that's not the dog's fault--it's yours.
4.) GO TO A PROFESSIONAL TRAINING CLASS: Professional trainers are friggin' amazing people who can help you IF YOU MAINTAIN AT HOME THE DISCIPLINE THEY SHOW YOU IN CLASS.
In the class I took with my current dog, I saw a German Shepard (who even I was afraid of) turn into a wonderful, in control, pet dog by the end of 10 weeks. The owner obviously took the class seriously, practiced between classes with his dog, and the dog benefited. Probably kept his dog from being labeled "vicious".
Professional training works with large AND small dogs. They stop behaviors like pulling on the leash and teach you how to communicate commands to your dog like sit, stay, (lay) down, and others you need to control your dog on or off leash. It is for their safety as well as other humans. But the dog only benefits if you take it seriously and continue the discipline at home. If you're a weakling, your dog WILL OWN YOU!
Whether you are a man or woman, YOU are the alpha in your house. Act like it and your dog will follow and love you forever.
Finally, just some short tidbits:
A.) People convicted of fighting dogs should be fed to the lions at the zoo. Once again, prove your superiority, macho man...
B.) Teach little kids to respect dogs and they'll be fine. But a little kid who kicks, hits, jumps on a dog is asking to get bit. The dog ain't vicious--it's protecting itself. Control your kid, dumb ass...
C.) All your dog asks for is food and love. Give plenty.