Fearful puppy

Question
I have a 9 1/2 month old Bernese Mountain Dog.  I got her when she was 3 months old and lately she is fearful of strangers.  She hides behind people she knows, if someone she is unfamiliar with enters the room.  I don't understand how to change this.  She was very well socialized as a puppy.  She met lots of new people all the in her first few months and was great with it. She actually came to work with me everyday and was always around different people all the time.  Then she had some medical problems.  Of course we had her spayed, and then in October (less than two months after being spayed) she was diagnosed and had surgery for elbow dysplasia.  It seems her fear of strangers began around the time of her testing and surgery.  She was left for a few hours at a vets office for tests and then overnite for the surgery.  Now, I don't know how to get my confident, unfearful puppy back.  What can I do?

Answer
There could be several thing going on including the fear stages puppies often go through at 4 and 10 months.  While she may have seemed to be OK at 3 months, that is really too late to socialize a puppy.  She may have missed socialization in the important 6-12 week period, and not been doing as well as it seemed.  Add the trauma of the spaying and surgery, and shecould have problems.  It is good yu are getting help now.  

When around strangers, remain calm, control your stress, and greet them calmly.  Don't coddle her.  You may need to recruit some.  Have them avoid looking her in the eye or show their teeth in a smile.  They need to keep their hands  away from the top of her head.  Have them offer her treats.

Obedience train her too.  The key to most behavior problems is approaching things using the dog's natural instincts. Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog. Life is much easier if the 2 legged pack members outrank the 4 legged ones. You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at http://www.dogsbestfriend.com/ For more on being top dog, see http://www.dogbreedinfo.com./topdogrules.htm  If she has you as a strong leader, then she should follow your lead in welcoming strangers.  

If none of the above helps, you may need to find a private trainer or behaviorist.