Sad to hear this as Shih Tzu's are usually very sweet natured dogs..perhaps he was provoked one time too many? I have a gate across the kitchen door so the children can see the dog but not bother her [or she them]. Looking at all the old photos I have,most of them have dogs and cats with the children [one of my dogs went blind at an early age and could easily have turned snappy because of it]. Not even just our family pets but holiday photos with other peoples dogs [my daughter cuddling a pointer we met whilst on a camping holiday in France, and a Bull Terrier at a hotel we stayed at; even, shock horror, my daughter sitting on a bench next to the biggest Mastiff you've ever seen]. Looking back we were lucky that they never got bitten by the dogs or scratched by the cats, although they were so used to animals from an early age they never provoked them. Thinking about it, though, my ex was always scared of dogs, from being bitten when he was little, and I think my niece has a scar on her face from a bite as well. Difficult, because I think it's lovely for children to grow up with animals,as they add so much to their lives.