There is a difference in breeds which have a propensity to bite and breeds who cause fatalities with their bites. I've seen some published studies which show that cocker spaniels are more likely to bite than a pit or rottie---HOWEVER, the bite of the pit and rottie are more likely to result in death.
There are several breeds responsible for the majority of death by dog bite each year--pits, rotties, German Shepherds, dobermans, etc.
I have a pit which we watch very carefully. He is never unmuzzled around children, ever. He is never out of the house unleashed. He is given the canine good temperment test (I think that's the name!) every year at the vet, and every year he passes. He does better on the test than my Yorkie! But he has great power, and knowing that, we treat him very carefully around youngsters. That's the least any dog owner should do, and it's for the protection of little ones as well as protecting your dog!
This little family we're discussing here, it sounds as though the mother, uncle and grandmother were very loving caregivers who made a mistake when "handing over responsibility" That is so unfortunate, and so sad.
