Never judge a book by its cover, this phrase is said round the world in so many different situations and should also be taken into consideration when purchasing the right type of dog for your children.
Most people are scared when they see a big dog being walked down the street. The have an automatic fear it will randomly attack just because it's a Rotweiller, Pit Bull or Doberman. When it comes to a little dog however they automatically assume they are cute and cuddly, stop to say hi and compliment the owner. Most of the time its the little ones you have to keep an eye out for. Most of the time their bite is worse than their bark.
Every dog has a unique personality and some small breeds such as Chihuahuas or Poodles are known to be sensitive and are quicker to act in defensive biting than other breeds. There are certain tests that can be done by animal professionals such as a vet or animal shelter worker where they can test a dogs sensitivity. One way to know if a dog is sensitive is through its paws, a dog who doesn't like being groomed or having its nails clipped may be the more sensitive and aggressive type than a dog who doesn't mind being groomed.
Most dogs who were not raised by children from puppies, are not very good with children's rough play. They become nervous and tense as children's curiosity can sometimes accidentally hurt the little animal who's only defense is to bite which is an automatic reaction as a dog when threatened.
From personal experience I can tell everyone that size doesn't matter when dealing with children and animals. Growing up my parents worked a lot of long hours and I spent the majority of my young childhood with our family baby sitter. She always had a small dog, her first one was a black and white shiatsu named Tatu. He wouldn't mind a pet or two from children however when enough is enough he would just simply walk away with no harm done. However, her second dog that I remember was a rusty colored long haired shiatsu mix named Nicky. She had been given Nickey by a friend of hers and Nicky, as cute as he was, was not a friendly dog at all. Our babysitter constantly told us to stay away from him and that he didn't like children. One day as I was playing with a favorite toy I had accidentally dropped it close to Nicky. Innocently I reached in to take the toy back and Nicky bite me on the hand.
Fortunately for me it was a minor skin wound that required a visit to the Dr's and a tetanus shot. I thought that every dog was nice, big or small because my next door neighbour had two German Shepherd dogs who would not hurt a fly. I remember being able to spend hours outside playing with them and not even being close to scared they would ever do me any harm.
Even to this day I have children of my own and own a large breed dog. A dog who makes most people's eyes widen in fear he might attack them just because he's a Doberman. My children are rough with him and he takes every bit of it, all 110 pounds of him. So it just goes to show you, it doesn't matter what the size of animal. It depends on the way they are trained, handled and of course as I said the breed and temperament of the animal.