[matese]

Every dog reacts differently to many things. This is not "normal" for any breed. This should be trained out of her using positive reinforcement.
I'll ya a lil story.
Many years ago my first dog as an adult was a toy Poodle but bigger than the standard toy.She was about 2 years old, it was winter, I was having difficulty removing my boots, I asked my (now ex ) husband to pull them off for me. When he went to pull the boot off MY dog latched onto his wrist, didn't break skin and let go just as fast. Well we all (my son) thought it was so funny that this lil dog was protecting me. As time went by, every so often either my son or husband would play grab the mamma's leg and MY dog would lunge at them. Now she is 10 years old, we had bought a house and had our first New Years Eve party, invited friends, family and neighbors all ppl that MY dog knew. I was sitting talking to someone to my left, a neighbor sitting to my right, wanting to get my attention put their hand on my knee, from out of no where MY dog is latched onto their wrist, let go just as fast. My neighbor was startled because of MY dogs reaction, this was a sweet loving dog. Because over the years I didn't train that out of her, thought it was cute, funny, things could have been a lot worse.
Reason I suggest train that lunging out of her using positive reinforcement.