the Dog could be trained not to do that...that is ALL the owners fault....the dog is 100% faultless.
edit;
thats not to say I would not have broke its neck protecting my kid. 
I noticed the dog had no collar so it was likely a stray! No one loves dogs more than I do but I think strays should be put down!
Any dog over about 40 lbs can be a dangerous animal,smaller dogs can do harm but a good football kick usually ends it! Larger dogs can take a human down and if there is more than 1 dog the situation can become very serious and people have been killed.
Pretty cool cat! It deserves an award!