Why is my dog starting to bite people all of a sudden?

I adopted a hairless chinese crested about 2 months ago. Untile this weekend she seemed to like everyone (people and other dogs) but for some reason she has been running behind people and biting the back of their legs. All of these people she has been around and seemed quite comfortable. The only thing that has changed is that is shaved some of her hair off her back and face but surely that wouldn't alter her personality. I don't know what has gotten into her! ANY IDEAS?Also, How do I correct this behavior?

it could have been some food she ate

if she's teething....then she is probably chewing on everything. how old is she? and is it aggressive biting or playful biting. your action towards it will differ depending on which one it is. sometimes vets offer counseling about bad behaviors. maybe call your vet and hear their suggestions.. they are the experts...yahoo answers...................not so much

So what happened this weekend? Do you have kids that may have taught her that?

A lot of times dogs will go through "instant" personality changes when they are experiencing some type of pain that you can't see on the outside. Ulcers, infected tooth, yeast infection in the ear, something lodged in the paw pad, are all common culprits. Before addressing the behavioral issue, I really suggest a trip to the vet to be sure there's nothing going on that you can't see. Also, keep in mind a dog you buy/adopt won't show its true personality until it has settled into the home, which usually does take a couple months. If all medical issues are ruled out, then you have to find out WHERE this aggression is stemming from. Is it being territorial? Is it resource guarding? Is it fear based? Is she doing this all over the house? Is she doing it near her kennel or food dish? Is she doing this to people who are coming towards her? If it's the first, it's probably territorial. The second, resource guarding. The third, fear based. Territorial and resource guarding can be corrected the exact same way, fear based can be more involved. When she goes to nip someone, put yourself BETWEEN her and the person. Walk towards her. She should immediately back up. Tell her "NO." in a low voice, don't yell. Repeat this several times. She should eventually lose interest in the person. When she is calm and minding her own business, have the person she was aggressing towards give her a small treat. If when you try to block her, she slips between your legs or still won't lay off, I suggest putting a leash on her. I would use a normal leather or nylon collar and not a choke chain as the Chinese crested doesn't have much fat/hair to protect her throat. Give the leash a hard tug, and say NO. Immediately force her into a position on her side (gently, but firmly). She will probably scream, wiggle, and possibly even bite. Still, don't let her up until she is quiet and holding still. When you let her up, odds are really low that she will go for it again instantly. If she does, repeat. You will have to work with her for quite awhile until she is reliably not going after people. CONSISTENCY is the name of the game here. You (or someone else who won't panic or use a high voice) must be able to do this EVERY time she tries to bite. If this is fear based, you need to find the variable that is scaring her. Lots of new company, a friend visiting with their dog, someone's child pulling on her? Look long and hard for something that could be scaring the dog. I also recommend getting her on a predictable routine. This should help immensley (also do the actions I suggested for resource guarding/territorial behavior) Dogs thrive on having a schedule. Feeding, walking, playing, etc. all at the same time. It's very soothing for a dog to feel like a member of a stable pack. Also be sure she is getting enough walking, a dog with a lot of energy can direct it towards negative things. Hope this helps, good luck!