Shy

My dog was wonderful with strangers when she was older. but one day a strange man walked up and struck up a conversation and she was NOT happy, she groweled and barked and her hackles stood up and she backed away from him.

Perhaps something about the man told her that he wasn't "good".....

IF this is happening with other people, then you need some help. She
may lack confidence... and a decent obedience class will help her with
that. She just may need to meet more new people in a situation which is
very positive... like the new person offering her goodies in a quiet
voice and petting her without the hand coming directly into/over her
face to her head.... under the chin or into the side is Much better.

Given your other post, I think you'd help yourself a great deal if
you'd pick up a good basic dog care and training book and do some
reading. I like the "...... for Dummies" and the "The Complete Idiot's
Guide to....." series as they are easy to use, written by people who
really know what they are talking about, and reletively inexpensive.
These books explain what and why, as well as how....

Jo Wolf
Martinez, Georgia