I was afraid you would say that.
At 15 wks (basically 4 months) the pup should be force fetching. What's meant by that is he should retrieve a dummy, bring it to you, and keep it in his mouth until given the "Drop" command. To do this you should start by putting a dummy in his mouth and giving the "Hold" command. If the pup wants to drop it you might need to cup your hand under his lower jaw and keep him from dropping the dummy. Don't make him hold it very long at first (3-5 seconds at most), but take it from him when you give the "Drop" command. Work your way up to longer amounts of time after you stop using your hand to keep it in his mouth.
A few things to remember:
Don't get frustrated. He can tell it, and if he knows your frustration will get him out of work he will use it to his advantage.
Work time is work time. Be firm, but not frustrated. Don't let him play when it's work time. After and only after you've finished working your pup should you allow him to play.
You might want to buy a shock collar. Some people don't like them, but dogs listen much better after you let em know who the boss is.
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