agressive behavior increasing through my puppy

Question
My name is Lara & my 11 month old English Pointer is Boone. I got Boone when he was 10 weeks old and I had rescued him from a local shelter. Since then, he has always been skid-dish around people, loud noises, anything (which I understood he may have had a bad situation before he was put up for adoption.) At first he was just scared like most puppies, but I had lived in a condo with another girl, her 2 year old mini dachshund, and her boyfriends 2 year old Australian shepherd. The dogs were fine with each other, Boone had been socialized very well (people were constantly coming and going and he enjoyed it!) I got a place of my own when he was around 7 months old and he got a little more protective of me. He will bark & howl at people but runs away when they try to pet him. He's always enjoyed other dogs but now that he's older he has gotten to the point where he will growl at adults, children, he won't let other dogs near me. And this behavior comes and goes. the vet couldn't give me a straight forward answer. She did suggest that it may have been around the time I was on my menstrual cycle and he recognized that. But it's just hard to take your dog to the park when all of the other dog owner's worry for their dog's safety. He's the sweetest dog in the world to me and does well with people he recognizes, but every now & then (especially when toys are involved) he gets extremely aggressive. And once a fight breaks out between him & another dog, it takes all I have to get him to stop because he's increasing in his size (he's about 65 lbs. now.) I just don't know what treatment can stop him if he will listen to me any other time except when he has these mood swings. Please please please help!

Answer
This is extremely aberrant behavior for the Pointer.  (He's neutered I hope.)  His "protection" is based on fear.  For a dog that's been so heavily socialized (as you report), this is unusual.  It suggests you have somehow rewarded this fear along the line and it certainly suggests that the dog is without adequate psychological leadership (from you.)  His dog to dog aggression precludes you taking him to the dog park (obviously) but may also be fear based (I can't see that from here.)  Because he is trophying toys (as you describe briefly), and because his aggression toward people has escalated (and includes children), you need first hand evaluation by a certified applied animal behaviorist.  This expert will evaluate Boone's temperament, do an in depth interview with you, observe your household situation, teach you how to use positive reinforcement training to turn his anxiety and fear around by providing strong, calm leadership, and put him on a behavior modification protocol.  I also suggest you find another veterinarian, because your vet's suggestion smacks of flat out ignorance.  If you are in Britain, contact the Association of Pet Behaviour Counselors or go to this site to attempt to obtain information regarding a behaviorist:
http://www.coape.co.uk/

If you are in the US, contact the veterinary college in your geographical area.  DO NOT hire a dog trainer; your dog requires far more expertise.