How to teach your dog to hold something in its mouth?

I was going to say put drop on cue, but it already is.  So take it, drop, c/t. 

take it, drop, c/t

take it...drop, c/t

extend between the take it and drop if possible and only c/t the drop part on cue.

I'm not sure if it will work, but it's worth a try. 

I agree with Tashakota, if he knows "hold" and "drop it" I would gradually increase duration of the "hold" command.  Maybe hold for 1 second, then ask to "drop it", next time hold for 2 sec, etc...you get the idea.  Clicking and feeding each behavior. 

I tried that. The problem is that Neiko is very anxious to get things right that he gets extremely frustrated and will drop what he has and try something else, thinking that he did it wrong. Maybe I'm extending it too long and need to do it in nanoseconds or something 

Edited to add: you can't treat the take because that makes him drop it and you can't treat the hold before the drop command for the same reason...I think. 

If the problem is length of hold, I would quit worrying about drop for a while.  Hold... c/t and let him decide to drop it to take the treat.

Remember, you have to work on one thing at a time and let other things slide.

Or conversely, only reward if he drops something you have asked him to drop.  This will be harder I think and take longer...  So you are working on drop and only on drop.  But he only gets rewarded for dropping on command.  Not when he wants to.  If he drops it w/o a cue, then no c/t.  You may even have to walk away from the training at that point.  If this is done right, he will be grabbing everything in site in order to be cued to drop it to earn his reward.  But I'm not sure I can help with finer points of doing it this way.

I would probably work on the hold and he can only drop it if you click.  

It's a tough one....  I'm still excited to have my dogs go after something and bring it back.  ;) 

That makes a lot of sense: breaking it down to hold and drop by themselves. I think I'm trying to rush both things together. 

a helpful hint for complex behavior chains: always train them backwards. Start with the very last behavior, and don't proceed until you have pretty good fluency with that one. So here you shouldn't be working on anything except "drop it" only on cue until he gets that down- even if you have to physically place items into his mouth in order for him to spit them out at first. So say for the carry sock from floor to laundry basket, what's the last behavior? spit out the sock. Second to last behavior: put head over laundry basket. third to last: move to laundry basket while carrying sock. First behavior: locate and pick up sock.

You could try this....it worked on my Dobe, though I haven't tried it on any other dogs yet.  ;)  When he has the object you want in his mouth, tell him hold it, and stroke him under the chin and gently on top of the nose(stroke toward his nose).  Don't continue saying the command (that would make him think that you want him to do something else), but praise him.  I'd do like the others suggested and only do this for a few seconds at a time so that he can have success. 

 You might find this link for the backchained retrieve helpful.  This is how I trained Sioux to retrieve a dumbbell - and she is a dog that hated putting anything (except food) in her mouth.  She has never failed to retrieve the dumbbell since we did this work.  And, the "hold" was the part she had struggled with.

http://www.dogscouts.com/retrieve.shtml