obsessive chewing

Question
Hello!  I have a 2 year old male Golden Retriever. He is a wonderful, smart dog with all of the typical 'golden qualities', (loves the water, carring sticks, etc). I am at the end of my rope however, on one issue.  Whenever I take him outside, he makes a point of finding pieces of wood and then chews on them and swallows them, which he vomits up later. He does this almost obsessively. I have tried everything to stop this behavior - he's always on leash so I am always there to catch him in the act. I've tried countless corrective jerks with his choker (which he's oblivious to because he has a very high tolerance for pain) and I've used the command 'drop it' which he knows very well and will do this when he feels like it. Most of the time however, the words 'drop it' translate to 'I'd better hurry up and swallow it before they fish it out of my mouth'. I have had to resort to muzzling him when we are outdoors, but don't want this to be a permanent solution, obviously. Do you have any suggestions for controlling this behavior?  I hoped that he would grow out of this, but now that spring is coming he's right back at it and it makes any downtime outside impossible. Thanks so much in advance.

Answer
This is a tough one.  Have you checked with the vet?  Most dogs do slow down on chewing by age 3.  You could gain more control with a head collar.  The leading brands are Promise,  Haltie, and Gentle Leader.  They have a strap going around the dogs nose looking something like a muzzle.  They work by pulling the dogs head around.  No other way gives you such great control with so little force.  Be very careful not to use the same snaps of the leash you do with the slip collar.  

It is hard to go anywhere outside and not have sticks to chew.  Many dogs eat grass and throw up too.  I am not sure if they do it intentionally, or just never learn.  

You might touch up his obedience training too.  The dogs see all the
people and dogs in the household as a pack with each having their own rank in
the pack and a top dog.  Life is much easier if the 2 legged pack members
outrank the 4 legged ones.  You can learn to play the role of top dog by
reading some books or going to a good obedience class. A good obedience class
or book is about you being top dog, not about rewarding standard commands with
a treat. Start at http://www.dogsbestfriend.com/