newly adopted 6-10year old yellow tried to bite friend

Question
Jen,

First of all I'm so sorry for writing a short novel to you but I wanted to get as
much info to you in hope that you may have some thoughts as to what we
should do with our recently adopted 6-10 yr old neutered male yellow lab.
My wife and I adopted Sailor from lab rescue. This is our 4th adoption through
Lab Rescue. To be clear the other three dogs passed on and Sailor is the only
dogin the house.  But he shares the house with 3 de-clawed cats. We have no
children.
Lab Rescue had scant history on Sailor. We do know  he was a stray picked up
about a week to 10 days before we adopted him.  We talked to his foster who
said he was a very sweet boy and didn't chase her cats.
He is very sweet. He is also very anxious and always under our feet to the
point of annoyance.  He pants often. We think he just needs to adjust to us.  
Over the last 3 weeks he has gotten marginally better.  

After we got him, we found out he he does want to chase the cats but he
doesn't really seem that into it.  He only chases them for a few feet and stops.  
We strongly correct his behavior (NO!) and that does it.  He still shows interest
in the cats.  Anyway the cats don't seem that afraid of him.

Last Sat. we had a disturbing incident.  My friend was over and was meeting
our dog for the first time.  He was by the front door and my wife and I were
talking to him.  Sailor (our dog) came into the living room.  We announced to
our friend that this was our new dog.  He is a dog owner himself with 2 labs.  
He put is hand down for Sailor to sniff.  Next thing we saw was Sailor snipping  
at his hand and then trying to bite our friend on the leg. He didn't but had
grab of his shorts.  We instantly pulled Sailor off, put him on the floor and No!
him.  My friend wasn't upset and Sailor did not break his skin.  We were
shocked.
Afterward Sailor was very submissive and licked my friends hand to make up.

Outside of our dogwalker (who is male, my wife thinks that Sailor may have
been abused by males in past)

Sailor has barked at our male neighbor through the fence.

We are worried.  We contacted Lab rescue to see what we should do.  So far we
heard that they would take Sailor back but have been vague about what they
will do to him. Mainly because they don't know themselves yet. However they
did say we would bring him to a kennel.    I haven't heard if they will put him
down, but since he's kindof old they may want to do that.  Anyway, Lab rescue
will call us in a couple of days with instructions.

I don't want to take him to a kennel.  He's only been with us three weeks but
we have provided him a good home and I can't bear the thought of him in a
kennel while being evaluated or waiting to be euthanized.  If they want the
dog euthanized I would take him to my vet and have it done.  At least I'll be
with him at the end.
My dogwalker told me he has a very aggressive dog at home. THey  put their
dog in a room when guests come over. That could be a solution for us as
well.  But I am still concerned that if Sailor is in our back yard and one of the
Neighbor's kids comes in that Sailor would attack.  Accidents do happen.  
BYW, when I told my dogwalker this, he was very surprised as well that Sailor
would try to bite. Like I said, he is a very submissive boy.

I guess I'm trying to balance doing what's best for Sailor and what I need to do
as a good neighbor. Is keeping a dog I know can be potentially a biter
manageable or we I playing russian roulette.

Any thoughts?

Answer
The dog is in a new environment and 3 weeks may not be enough for Sailor.  Why not enroll in a refresher obedience class?  The dog will get re-socialized to men/women/kids/dogs in a busy environment and then in the event that something does trigger him to get snappy, you will have a trainer there to help intervene.  

There is nothing wrong with putting the dog away when there are guests.  And if you have to put the dog in the backyard, you should be able to tell your friends and neighbors that their children are not allowed in the backyard without parental supervision...PERIOD.  Invite the neighbors and kids over and explain why they aren't allowed in the yard.  

I think with some time and training, you should be able to get over this problem.