Our three-year old tripped over the dog and then somehow the dog (a big black lab) fell on him, breaking his upper leg. The emergency department questioned each family member separately. It was as if we had something to do with it. Is that standard? The more I think about it, the angrier I feel being treated like that.

It sounds like your child had what's called a diaphyseal femoral fracture -- a break in the middle of the shaft of the upper thigh bone. This is an uncommon injury in a young child. Usually, there is a traumatic cause -- either a car accident or unfortunately, in someone this age, possibly child abuse.

Older children may sustain this type of fracture as a result of a sports injury. The cause as you describe it certainly accounts for the trauma that could break a young child's bone. In any case, according to the American Academy of Orthopaedic Surgeons (AAOS), any child under the age of five (and especially any child younger than three) should be examined carefully for the potential of child abuse.

Your patience with the process was probably appreciated greatly by the hospital staff. No one likes to be asked those questions or have to be the one to ask them. But you can understand the importance of finding out for the safety of the injured child if, in fact, there is anything more than the accidental trauma described.