Great Dane Food aggressive at 4 mos

Absolutely stop free feeding this dog.  He thinks he owns the food.  You, as a leader, should own the food, and share it with him.  Put his bowl down for fifteen or twenty minutes, then take it away till the next feeding.  Or, better yet, hand feed him for a couple of weeks, kibble by kibble - then have your hubby do it for a week or so.  Run, don't walk to dogwise.com and buy a copy of Jean Donaldson's book "Mine! A Guide to Resource Guarding in Dogs".  You must control this dog's resources, and that means food, space, resting places, etc. 
Dogs that don't get nasty about their kibble will guard "special" stuff - things like bones, pig ears, and, yes, eggy spatulas.  You need to get this training done NOW while he is a pup, or it won't be pretty when he's two.  Have you been to classes with him?  If not, sounds like a perfect time to sign up.  Use a positive reinforcement trainer who does not employ harsh tactics or you may end up with something other than the dog of your dreams.  Food aggression can be treated, but requires the participation of everyone in the dog's life - some dogs learn not to guard with one human, but will guard with others.   For the safety of your child, please do keep the dog secured while humans are eating. 

He is getting to the point where even when you just get close to him he will growl but if you call him away from it he will back up. when i refill the feeder he will stand there and watch he never makes a sound never.... he has never acted this way til now i have had him a month and a half... any advise as to why he is so thin looking i think it is metabolism but i am not sure...

If he's overly thin, and guardy about food, first thing I would do is get him to the vet and have a wellness check, plus insist on a full thyroid panel.  Thyroid problems can contribute to aggressive behavior.  If that turns out OK, please seek help from a qualified behaviorist.  PACLeader may have some additional advice for you if you PM him.
If he is growling, then getting silent, or freezing, or looking at you with "whale eye" (the white of the eye really shows), these are not good signs and you do need help.  If this large a dog finds out that he can tell you where you can and can't go, life can get dangerous indeed.  Get professional help, and just make sure the person is qualified (Animal Behavior Society, IAABC, etc.)  If you need a referral to a behaviorist, call the nearest veterinary college.
The dog may be starting to feel more comfortable in your home, but that can sometimes mean he feels comfy telling you what to do (or, in this case, not do).  He's too powerful to let this continue.
You can PM mudpuppy, too.  A very savvy Great Dane owner.

Definately stop free feeding until you get a handle on the problem. Training for these big guys is a must.

I can help with some basic Dane feeding guidelines-

Do NOT feed puppy food unless it specifically formulated for giant breeds. Slow, steady growth is best and don't let the pup become overweight.
At 4 months old the pup should weigh about 50-65 lbs and be 21-25 inches tall.
You should be feeding a total of 4-6 cups of food per day, Split into 2 or 3 meals or hand fed as suggested above.
You will need to increase the amount of food by 1 to 2 cups per day every month as the pup grows. Our adult males are small (125ish lbs) and eat about 6 cups per day. 3 cups morning and 3 cups evening. But young males can eat up to 12-15 cups per day.

A good reference site for Danes and more feeding info is www.greatdanelady.com

It's VERY important to feed your great dane puppy in a particular way or you are going to have expensive problems like pano, knuckling over, HOD, and possibly hip dysplasia, bone cancer, bloating...
 
 
What are you feeding?   the only food that has been proven to prevent bone growth problems in great dane puppies is Eaglepack's giant breed puppy food.
You CANNOT free feed these dogs or you will end up crippling them. You want the puppy to be very skinny, and you must control the amount of food the puppy eats. Two meals a day of pre-measured amounts.  Mixing wet foods (canned, homecooked) in, and/or adding chunks of meat, will help prevent bloat.  I don't think great danes should ever be fed completely dry meals because of the high risk of bloat, and they certainly should never be allowed to eat as much dry food as they can consume out of an auto feeder. You'll kill him. Throw that thing away.
 
Get the book Mine! and follow the protocol on treating food guarding.
 
A four-month puppy should not be expected to "go out" by himself. You need to be taking him outside on a set schedule and rewarding him vigorously for pottying in the correct locations until his is at least six months old, possibly older. It never hurts to praise a dog for doing something right.

Dane mom, welcome to this forum and I commend you for seeking help with your large pup and his all of sudden strange behavior.  Remember he is is a pup and remember you are the one in control and the advise given from these experience Great Dane owners is good.

Posters, don't scare an already scared mom.  OP listen to Danehaven and reference those sites.  They are very helpful. 

OP, what brand of food are you feeding? 
 
What kind of training have you been doing? 
 
I would begin with the hand feeding and then in a week or two move meal time to the crate.  Offer 15-20 minutes to each and then it's done.
 
How is his bite inhibition in general? Is he rough on your hands? 
 
What was your reaction at the time of the incident?
 
 

Ok first off maybe i wasnt clear on what i was saying he is not gorging him self he eats small amounts thru the day he doesnt eat it all at once and he doesnt bloat he eats small amounts but very quick then he goes out to potty and then he takes a nap and starts all over again and when he does anything good he always gets praised he has been to the vet and has a clean bill of health but he is thin i asked the vet and he said that he is a typical dane pup... he is eating Diamond Large Breed Puppy with some vegetable oil mixed in

Hi and welcome!  I also have a Harl Dane.. as you can see from her picture!
Please listen to those ideas above. Spritdogs helped us thru several bouts of problems when we got Bubblegum. The difference is that she was already 3 yrs. old when we got her from the breeder.
I get the feeling that your dog is doing what mine started to do....as she got comfortable with her home and surroundings..she started to want to kind of protect it.   If I give her a raw bone to chew on,,, she is fine with us,,but yet if you really watch, you can see her stiffen up when I get close. BUT I ALWAYS do get close,, just to always let her know I am in charge.
Its true, she will get big one day and you need to get this taken care of while she is young and smaller. DPU is right,,,do not be afraid. Just take charge!  Danes are the sweetest most loving dogs, but they do try to take over. Bubblegum still does. I have to constantly reminder her who is in charge. Taking your dog to training will help with that.
Eagle Pack is the very best food for a Great Dane that you can feed. It is the only food trial tested on giant breeds.  The link that Danehaven suggested ([linkhttp://www.greatdanelady.com/]www.greatdanelady.com[/link]) is my DOGGY BIBLE! I go there all of the time.
I have slowed down Bubblegums eating by adding a lot of water to her kibble. She eats about 2 and 1/2 cups of Eagle dry, I add almost a cup of water to it. I do NOT soak it, I just add it and feed her immediately. It has slowed her down a lot. I also worry about bloat. I put a probiotic supplement on her food, to help prevent bloat.
Hand feeding your dane is an excellant idea. It makes them know that YOU are feeding them. I also make my Dane sit and wait until I tell her its okay to eat. I feed her one time a day, I have my husband feed her the other..he also makes her sit and wait until he says OK.
 

he is eating Diamond Large Breed Puppy with some vegetable oil mixed in

 
Just wanted to say that when I got Bubblegum from her breeder, she was eating Diamond. She told me that if I did not continue to feed Diamond she would not give her to me.  I told her I was going to feed her Eagle Pack which is what we feed Ollie (my sons Dane who was at my home more often than not) and she said "oh, thats better for her than Diamond so thats okay!"

We have just been working on manners and basic obedience sit stay "here"(come)
he is doing great with everything except food aggression and it was so sudden i just wondered what struck his match? he never bites for any reason until here lately he is play biting alot.... here is the thing the lady i bought him from has a 4 yr old son the literally romped him in the floor daily the dog loves it but i cant allow it with a 10 month old i have broke him of that everytime he started we used the term settle and we sat him on his butt. until he settled down he was very mouthy then and he still is a little on the thought of restraint. if you hold his collar in anyway he is trying to bite your hands but he WILL NOT bite you to hurt you and he has NEVER broke the skin.... right now we are working on "NO PAWS" he is bad about if you are sitting in the floor with him or you take him for a ride in the car he will throw his paws up at you and it hurts if he gets you. but we have almost accomplished that task. he is an over all good dog it is just that with a small house and a 10 month old son constantly in a walker and a 4 month old aggressive dane it is becoming more dangerous than anything... there isnt a gate in the world strong enough to hold this guy in either. we have tried.

Using their paws is a "dane thing!"  Not that long ago I ended up at the doctors because Bubblegum paw was in my eye. You CAN'T be too careful about danes and their paws.
 

he is bad about if you are sitting in the floor with him

  Both Bubby and Ollie,,,seem to get a little aggresive when we get on the same level, such as sitting on the floor with them.  They seem to know that then they are bigger than you. Extra attention and guidance is necessary when you are at their level..or smaller.
 
I live in a very small house, with a sometimes very wild Dane. They get "crazy" when they are feeling rambunctious or need exercise.  Honestly, if you have your dog trained properly, you don't need a gate strong enough. I had a Dane/sheperd that would not step over a  "barricade " of a yardstick in a doorway. 
 
There are way too many Danes in shelters looking for homes. Many (maybe most) are there because they are big strong dogs that people bought as cute little puppies,,and didn't realize how hard it could be to live with them when they are big.  Your dog is still young and you can do so much with him,,but you have to do it now while he is still young.  Having such a big dog in a small home with a baby is tough,,, but you can get thru this all if you try.  I do think though that you will need a little extra help though with some of these issues.  Bubbys breeder told me once that Bubblegum was the smartest dog that she ever had..that she is constantly trying to outsmart everyone.  She was a showdog and had been taught quite a lot before I got her...but you almost never knew it. We need to constantly be working with her... she takes over easily.

Great dane puppies can be a handful all right, but keep in mind they just get bigger. You need to start training from day one so you can maintain control of a dog who is larger than you and can't possibly be physically forced to do anything. Get to puppy class now.
 
it's fairly easy to cure the food guarding, but you really need to stop the free-feeding. You need to take control of the food for his health and for your safety. It is instinctive for dogs to guard food, it has nothing to do with "dominance" or "whose the boss"-- people often assume that it does, and make the big mistake of using force and violence towards dogs who are guarding food, and unfortunately that just makes the dog even more sure he needs to aggressively guard his food.
 
What you want to do is teach the dog that YOU WILL NEVER attempt to forcibly take the dog's food away, so the dog relaxes about having you near his food, and you also want to teach the dog that if you do mess with his food, he'll get something better in return-- so now he's actually eager to have you come near him when he's eating because he anticipates you might add a delicious treat to his bowl.
 
Look up NILIF and do get hold of a copy of Mine!. It explains in detail how to prevent and/or fix resource guarding.
 
 
 

I fed him last night with me holding his food bowl and him eating out of it and he didnt want to eat out of it that way... he nearly refused to eat with me holding the bowl but he did eat out of my hand if i fed him the food by hand... and i could pet him the whole time but if i got close to his face he gave a deep snarl and growl as if to say back off and i didnt i kept my hand there until he stopped and then i backed off and took his food and gave a treat but if i put the bowl on the ground he is growling and the thought of someone touching him again.... i put my self between his face  and the baby last night while he was eating and the baby reached over and pet his side and dudley looked up at him and then just started eating again. i dont know what his problem is with me i have never taken his food away or anything like that i just dont understand his behavior change unless it is that he is comfortable in our home now and this is the true him....[]