Dog food, and Behavior problems

Question
Hello,

  My name is Brad.  I have a full blooded Jack Russell Terrier male, that will turn 2 on April 1st.  I have been feeding him Purina puppy chow since I've
had him at 9 weeks old.  What I was wondering was, how long are you supposed to feed him puppy chow before switching to actual dog food?, I heard about
2 years, but no one I talked to knew for sure, and should I stick with the same name brand?

My other question is:...  I've never got him neutered, and he is getting to be very protective of bones that I give him, and even my fiance.  For example:
When I give him a bone he'll take it and lay beside it, and if we even go near him he growls and shows his teeth, but he has never actually bit us.  another
thing, when he is laying in bed with my fiance, and when I come in the room and sit on the bed too, he acts like he don't know me and he growls at me,
like he doesn't want me near her, but he's nice to me any other time.  It's just during those times I mentioned that he's bad.   Is this because he's not
neutered?  I've also been told that when dogs do that, you should try and correct them, and they will grow out of it, but when we try to correct him, he
growls louder and meaner...

What do you suggest?

Thanks alot

Brad

Answer
Disregard anything else whoever told you he would grow out of it said too.  As he approaches maturity at 3 years old, such challenges to your leadership will only get worse.  The key to most behavior problems is approaching things using the dog's natural instincts.  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/  For more on being top dog, see http://www.dogbreedinfo.com./topdogrules.htm  Go ahead and neuter him too.  the sooner, the better.  An aggressive dog is a very poor candidate for breeding stock.

With large breed dogs, an early switch to adult chow makes for slower growth and sturdier joints.  I doubt switching now would be any problem for a smaller dog.  I think the dog chow companies push the 2 years because they have a higher mark up on puppy chow.  Many ''experts'' buy into their marketing hype.  If he is doing fine on the Purina puppy chow, I see no reason to switch to another product.  When you run low, pick up a bag of the adult, and work it in until after a week, it is all adult chow.  Don't listen to negative talk about the Purina.  It is mostly marketing hype from those selling more expensive chows.  There are no tests available to the public showing the more expensive chows are better for dogs.