Agressive pet dog

Question
QUESTION: Hi,
My dog Besti is a 9.5 year old female mongrel that i have had since she was a month old.She has never been tied up, sleeps on my bed and has been pretty pampered. Normally she is a dog that wants petting and affection and was absolutely safe till she was about 5.I could just carry her around and stuff. Then she started biting people all of a sudden, like a knee jerk reaction when someone would touch her without her having asked for petting. She has never been friendly with unknown people but she has bitten me too a few times too in this manner. Cannot predict what will irritate her, she just suddenly springs. and usually it is not a "serious" bite(like she does not tear out flesh) but sometimes a tooth does pierce the skin. I personally feel she started this behaviour a few months after her neutering operation which was probably a traumatic experience as she would not allow the vet to anesthetize her easily and had to be tied up and held down by unknown men. This was when she was about 2 years old. I am really concerned as the family has to be extremely watchful and careful not to go too close to her when she is sleeping and not to irritate her.  Is there a solution to this..? Is this a mental disorder..? How should we handle it..?
Please help.

Ps - She has littered once and her daughter lives with us. the daughter is a very docile and friendly dog, never done anybody any harm. The two get along well most times, they do fight at times but nothing very serious.
She is quite a small dog. A little bigger than a Pomeranian.

ANSWER: Hi,
It doesn't really matter what the reason for her starting to bite, but I need to ask a question and you need to get back to me before I answer this question.  What were the consequences the first time she bit you and all the rest of the times after that.  When she nips or bites what are her consequences.
nancy

---------- FOLLOW-UP ----------

QUESTION: The consequence is she is yelled at and reprimanded, through out which she is still snarling. but no one has ever hit her. Five minutes later she wags her tail and seems ok again.

Answer
Ah Divya,

The problem is more serious than I thought.  The fact that Besti was yelled at and she still snarled meant that she felt she was still winning the argument.  From very young she should have been lifted and put on her back and made to stay that way until she relaxed and submitted to you.  If she started to rise, she should have been put back on her back again and again until you won that argument and she finally stopped her growling.

So lets tackle the problem.  First there is no mental problem except she is taking more and more control.  She is becoming the pack leader more and more as she gets older.  So we will start slow to test her like she is testing you.

First, if she doesn't already have one on, put a slip lead chain collar on her; a very fine one since she is little.  Also, get a short agility strap that hangs from this and when you are home these two things should be on her.  Not when you are not home.
http://www.cleanrun.com/index.cfm?fuseaction=product.display&Product_ID=1344&Par
You will use this collar and lead to help reinforce commands you are teaching her.  Catch her before she runs out the door etc.

I want you to start retraining your dog to commands.  She is to sit before you feed her.  She is to sit before she goes out and not move until you say it is ok.  This is a way for you to start to get control of her again.
You are to eat before she does at all times and so should your family.  She is to stay on her bed or be put into a crate while you eat.  Then she must sit and then be fed.  This will take some patience on your part because she has been getting her way for nine plus years.

If you do this every day, you should start to see a little improvement in about three weeks.  If during this time she snaps or growls, you will reprimand her as always, but you will stare her down, no matter how long it takes, but be careful, when you stand over her, but keep hands and face clear.  If she escalates, stay calm, but remain standing over her, if you have to get out of the way if she lunges, do so, but come right back.

If you can get some videos of Cesar Milan, do so, a picture is worth a thousand words.   Always remain calm, but assertive, not angry, it does no good in this situation.  When she finally glances away (just a blink sometimes) you have won the argument.  Do not give a lot of praise, just change the subject by asking her if she wants to go for a ride or go out.  Something she likes to do.  We want to change her thinking from aggression to a positive thought.

When this starts to work with her, it will take less and less time for her to submit to you.  Now, you mentioned she wakes up snapping.  She is almost 10, her hearing may be less than it was and she may not be aware that you are approaching, always call her name before you approach her.  Any dog may bite if woken suddenly.  It is a deep instinct, so please try not to put her in that position.  If she doesn't respond when you call her, you know she isn't hearing as well as she used to.
Dogs that are getting older suffer from the same things that humans suffer from; arthritis, stiffness, etc.  It is possible she is in some discomfort.  Petwellbeing.com has some great natural choices for older dogs.  I have used them on my own dogs and it has helped them very much.
A vet check might be called for too, to see if she has any joint swelling or any discomfort.  Check her ears and teeth.  A toothache is a terrible thing.

Well that is about all for now.  I don't want to overwhelm you and this is a good start for you.  If you do all of the above and there is no improvement please write me again.  I have other things to suggest.
nancy