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
Raising Your Dog with the Monks of New Skete For more on being top dog, see
Establishing and Keeping Alpha Position Follow the link on that page to their page on dogs and children.
Depending on how old the dog is, its genetic makeup, and early socialization, you may or may not be able to solve the problem. It needs to immediately learn you are in charge, and all the children outrank it. I am going to backslide from my following the current trend to more positive methods. Growling at a child is a serious problem, and needs an immediate, stern correction. Take a squirt bottle and fill it with water and a little vinegar or lemon juice. Give it a squirt in the face as soon as it growls at the child.
It also needs to learn that it will eat what you give it. Finicky dogs that hold out for tastier chow are a common enough problem I have all the information you need in the sticky at
http://www.askmehelpdesk.com/dogs/in...tml#post254171
It really sounds like this is a dog that has been allowed to do as it pleases. Quite often all it takes is a strong hand. You do need to act quickly and it will be a long time, if ever, before you can leave it alone with the chiildren. This may be a case where I have to side with those saying never.
Many dogs are dumped because their owners don't know how to train them.
With the quality of much of the advice I see, I am not surprised. with the right training, many can be saved.