Statistically a dalmatian is the breed most likely to be aggressive.
Less likely to kill than pit bull, rottweiler, wolf dog, huskie, chow, or shepherd.
Naw, there's no evidence of that.
Per the CDC:
"The denominator of a dog breed-specific human DBRF rate requires reliable breed-specific population data. Unfortunately, such data are not currently avail-able."
Oh ouch.
"Considering only bites that resulted in fatalities, because they are more easily ascertained than non fatal bites, the numerator of a dog breed-specific human DBRF rate requires a complete accounting of human
DBRF as well as an accurate determination of the breeds involved. Numerator data may be biased for 4 reasons.
"First, the human DBRF reported here are like-ly underestimated; prior work suggests the approach we used identifies only 74% of actual cases.
Second,to the extent that attacks by 1 breed are more news-worthy than those by other breeds, our methods may have resulted in differential ascertainment of fatalities by breed.
Third, because
identification of a dog’s breed may be subjective (even experts may disagree on the breed of a particular dog), DBRF may be differentially ascribed to breeds with a reputation for aggression.
Fourth, it is not clear how to count attacks by cross-bred dogs.
Ignoring these data underestimates breed involvement (29% of attacking dogs were crossbred dogs), whereas including them permits a single dog to be counted more than once. "
http://www.cdc.gov/homeandrecreationalsafety/images/dogbreeds-a.pdf