Help!!!!!!!!

Ok I have a 3 year old large dog.Hes super friendly familly orientated dog.Well he likes to eat which is no problem But he takes food from the counter somtimes.Well just 5 minutes ago I made horse cookies he went up to one & grabbed it.He ran so I ran after him,all I do when he does this is take it from him wait 2 minutes make him do somthing to earn it(sit stay ect ect)then he gets it.Well all of a sudden he swallowed it & came after me so I had to pick up my vaccume & scare him away.After I walked in the living room where he was on the couch & he growled at me so I said NO he then snarled & cam at me again so I through my shoe at him Maybe I shouldnt have done this but I was nervouse anyways he began to tremble & come at me.So I ran to the washroom which is right there & say go , he then ran past the washroom into my room.I then said Ben(his name)come,come here he wouldnt come so when I went to touch him he lashed out so I walked out of the room & shut the door.Now He has been in there 10 minutes & he wont come out without growlling or comming at me what should I do,& when He douse this again what should I do?pleaseeee help thanks

You need to call a certified behaviorist immediately. This is not something that can be handled over the Internet. It's gone too far for that. In the meantime, when he is not in a seperate room or crate, keep him leashed. Don't leave him leashed unsupervised though. If you can't watch him, put him in his own room. Give a treat when you take him in there. Do not let him come in the kitchen area when there's food around. Keep him off the furniture in the first place. Use your leash. Do not grab his collar or do anything which will make him feel cornered. Do not chase him. Do not take things from him. Keep them away in the first place. He will need to be re-trained to be willing to let you take things. This involves an extensive program of trading him for what he has possession of, among other things.... not throwing things at him, chasing him, scolding etc. You are putting him on the defensive by doing that and he's lashing out and disciplining you....actually trying to increase the distance between you and him by running you off. He has no leader and that is why he is making these choices. Please get help from a professional immediately. I'm very sorry this has come to this. Let us know.

I am terribly sorry! He needs a professional trainer I don't think you can deal with this by yourself. Keep him in th room for now, until he settles down. From this moment on he can not have treats like large biscuits or bones. Food guarding often develops from dogs who get stuff they steal taken away, he has learned the only way he an keep what he took is to attack/bite you. Work hard to keep all food items far out of his reach, if he does get something dangerous (if it is not just let him have it it is not worth the risk, but please try not to let him get ANYTHING) then use something better to get him away from it (meat of some sort or a bone with meat on it, anything you think he will like better and throw it pretty far so he goes for it, then once he gets over to it take the item he stole and dispose of it. If he was less extreme you could go through the trading up close but I fear just being near him while he has food would be enough for you to be seriously injured. You NEED a professional to help you with this at this point, hopefully some members can help you find a good one near you. If he had not actually chased you then i would not be quite as worried but there is no SAFE way for you to get the aggression out of him and then teach drop it and leave it (these are two commands that would prevent aggression with stolen items and also get your items back, at this point I think it would be too dangerous for you to teach these without a pro). We do have some trainers on the forum so maybe they know something you can do without a trainer but I'm not so sure... I really hope this ends up all right for you and your dog.

EDIT: Sorry I posted at the same time as Doberluv, take her advice she is much more knowledgeable than I.

Wait. Has he ever done something like this before? If not, then you should see your vet immediately.

That's what I was thinking also.

It's never a bad idea to check with a vet for any medical problems. Sometimes thyroid problems can cause changes in personality. And brain tumors and other things.

But just because a dog hasn't done something before, doesn't mean that it's abnormal behavior (from his point of view) that he appears to be behaving this way out of the blue. Conditions in the past and variables in his environment may have always been just so, that it didn't put the pressure on the dog to react this way. Everyone has a tolerance level and that can vary from time to time, between circumstances or contexts. For a long time, the climate for this kind of behavior most likely has been brewing, small things happening to increase the conditions to bring on this behavior and it finally got to a point where these responses let loose.

For instance, a dog can be fine and loving for a long time (we see it here all the time on this forum) and that's because all the conditions have been just right. No one has tried to take away the dog's food. Everyone has always reacted to the dog's demands. If someone tried to take a toy, perhaps the dog was already interested in something else and didn't care that time. He can tolerate a certain number of aversives....up to a point. As long as all those potential pressures have been skirted around and prevented from reaching a boiling point, all appeared to be fine. But when the combination of pressures that the dog is sensative to, come to a head and other variables are all set just so, the behavior flipped a switch. It's not that those feelings the dog had weren't there at all, at one moment and then they were. They were there, but just below the surface so no apparent (to the humans) problem existed.

Also, there can be signs the dogs are giving off that less experienced dog owners never notice.

In other words, unless this is medical, this behavior didn't suddenly, out of the blue just happen for no reason. And from the description, the OP is probably not an experienced dog owner. You hear so many people say, "He bit without provocation. He bit without warning....just out of the blue." That's all nonsense. He was set up to behave that way. Conditions were present which caused that.