I have a question, I've had my male lab/chow mix since he was born ( i took his mother in as a stray) any ways he is two years old and i've never had a problem with him as far as aggreseve behavior. I have three children ages 10,3 & 17 months old and he loves kids!! My childrens friends play with my dog and never had any problems. Well yesterday my friend came to visit and brought her children and they were playing with the dog for about an hour and the dog was tired and layed under the kitchen table and my friends 3 year old daughter crawled under the table an on top the dog and he snapped really quickly in doing so he must have bit her or scrapped his teeth off her head. which required 13 staples. I would have never thought this would happen. although i feel that she may have hurt him in some way by crawling on him. i'm still a little scared for my children should i be?? I also heard some wise tale that if a dog gets a taste of blood that will turn him mean. Is there any truth to that?? I could really use some advice I'm pretty freaked out.