@Basenjimamma:
I will see if I can find a behaviorist in our area, shouldn't be too hard I hope.
No Otis never bit any of us before Moses got here..maybe a clue. Moses is very large compared to Otis, so maybe that is one of the subtle clues I am missing, maybe Otis feel threatened by size. Otis is not neutered yet, could that be part of the problem?
..and you are all right, I shouldn't have to worry about being fast enough or nimble around any of my dogs in fear of getting lunged at..this is our house..not theirs, but they are allowed to share it with us.
My kids have rules not to walk around and eat and only to eat at the kitchen table, during the days if weather permits the dogs are outside, if not, I will start crating them so no opportunities are given to Otis to steal or attack.
Actually, that wasn't really the point…though it is a valid point! Being fast isn't part of the trading up. You want the dog to think that something GOOD is happening to him, rather than having something taken away...so the speed, or agility with which you do it should have no bearing...and actually doing things quickly, and frantically tends to raise the level of arousal, rather than lower it.
For a dog like Otis, who has shown you that he is willing to use his teeth to defend 'his' food...you will need a systematic approach to retraining him to let him know it is okay for everybody to take stuff away from him. It is a good preliminary plan to keep kids and dogs separate when food is involved, but you will still need to "re-program" Otis because accidents happen where people drop food, or something gets left behind and the dogs come in, etc.
Make sure the behaviorist/trainer that you choose uses a technique that makes sense to you. You need someone who will use positive reinforcement techniques, but also has experience in effectively dealing with resource guarding...you might ask for some references to contact. It sounds like the first bit of advice you got from your trainer wasn't bad...but didn't really do anything to address the problem.
Good luck, and let us know how it goes...