my yorkie hates toddlers

Question
My male Yorkie, Killer, is 1.5 yrs and not neutered. He has been with us his whole life and never hurt or roughed with by children. Since his very first time seeing a toddler he was aggressive- we were in an airport and Killer actually growled at the kid and tried to take his toy. Since then we've been with my neices who range in age from 1-8 and he just hates them. If the kids are quiet and sitting still he is ok, but as soon as he hears them or they move he's growling, barking, and on the attack. My brother-in-law actually intercepted an attack from Killer on my 2 yr. old neice. Even if he hears kids screaming or playing on TV he barks and growles. We have a 5 month old son who Killer pays no attention to, neither good nor bad. I don't want this to be an issue for my son or any other kids we have around. How can I stop this aggression? I had my neices quietly and gently give him treats which he happily took, but when they were loud again he got scared and tried to attack. What do I do??

Thank you!

Answer
There's nothing you can do to *guarantee* that children will be safe with this dog.  First, I would neuter him - reason being that he may be less aggressive in general toward other dogs, and possibly toward children he views as subordinate beings.
Secondly, I would suggest you not have children have direct contact with him.  When he is on leash, you can have a child toss him a treat on the floor, so that he starts to learn that kids aren't scary, and that they don't want his stuff.  However, the problem you have is likely because the dog was not socialized with infants and kids when he was a young puppy.  The things you want a dog to accept as an adult, they must see during the critical socialization period, between 8-12 weeks.  In the case of your own son, it's very much like what happens when a female pack member gives birth - the others in the pack accept the new *pup*.  But, adult dogs can draw the line with outsiders.  Also, if he is inclined to guard his toys or food, he is not safe with children and food/toys around.  The best thing to do is keep him contained while kids are playing, and vice versa.