The Clifton Study

Merritt Clifton, editor of Animal People, has conducted an unusually detailed study of dog bites from 1982 to the present. (Clifton, Dog attack deaths and maimings, U.S. & Canada, September 1982 to November 13, 2006.) The Clifton study show the number of serious dog-inflicted injuries by breed.

According to the Clifton study, pit bulls, Rottweilers, Presa Canarios and their mixes are responsible for 74% of attacks that were included in the study, 68% of the attacks upon children, 82% of the attacks upon adults, 65% of the deaths, and 68% of the maimings. In more than two-thirds of the cases included in the study, the life-threatening or fatal attack was apparently the first known dangerous behavior by the animal in question. Clifton states:

"If almost any other dog has a bad moment, someone may get bitten, but will not be maimed for life or killed, and the actuarial risk is accordingly reasonable. If a pit bull terrier or a Rottweiler has a bad moment, often someone is maimed or killed--and that has now created off-the-chart actuarial risk, for which the dogs as well as their victims are paying the price."

Clifton's opinions are as interesting as his statistics. For example, he says, "Pit bulls and Rottweilers are accordingly dogs who not only must be handled with special precautions, but also must be regulated with special requirements appropriate to the risk they may pose to the public and other animals, if they are to be kept at all."  

(Continue Reading Below.)

There have been many news reports about deaths caused by dogs in the USA. The attention given to the homicides has put the spotlight on pit bulls and Rottweilers. There is a very good reason for focusing on these two breeds: in recent years, they have usually been the number one and number two canine killers of humans. It therefore is correct to single out those two breeds when talking about canine homicides, because those two breeds lately have caused half or more of the deaths -- a disgraceful statistic whether it is regarded as the fault of the dogs, their breeders, their owners, or all three.

However, the focus on death cases may leave the public with the false impression that pit bulls and Rottweilers are responsible for the dog bite epidemic. It is a much broader problem than that, involving all dogs and all dog owners. While pit bulls and Rottweilers inflict a disproportionate number of serious and even fatal injuries, the dog bite epidemic involves many different breeds, and results from many different causes. A clear distinction needs to be made between canine homicides (i.e., incidents in which dogs kill people) and the dog bite epidemic.

The confusion caused by discussing the homicides and the dog bites in the same breath has its most important ramification in the area of prevention. Some are advocating the banning of pit bulls, Rottweilers and possibly other breeds, for reasons that range from their alleged dangerousness to the fact that they are very often treated inhumanely. Those who hear about the homicides often support breed bans.

However, while banning the pit bull might lower the number of human deaths, such a ban would probably not reduce the number dog bites in any significant manner. After the United Kingdom banned pit bulls in the 1990s, a study showed that the number of dog bites remained the same even though the number of pit bulls had steeply declined. (Study cited in B. Heady and P. Krause, "Health Benefits and Potential Public Savings Due to Pets: Australian and German Survey Results," Australian Social Monitor, Vol.2, No.2, May 1999.) However, there are serious deficiencies in how dog bites are studied, making it difficult to know for certain whether a pit bull ban would reduce dog bites in general. (See Dangerous and Vicious Dogs: the Problem With Statistics --> http://www.dogbitelaw.com/PAGES/danger.htm#statistics . Also see in next posting.)

As a practical matter, the current tide of public outrage should be focused on the enactment of measures that would deal effectively with the entire epidemic, not merely the breeds that kill. It would appear unwise to enact all kinds of controls on one or two breeds, not necessarily because it would be unfair, but because it would produce narrow and therefore unsatisfactory results. The war against crime isn't a war against just the bank robbers, but against all criminals; the war against drugs isn't a war against just the Colombian drug lords, but all drug lords. For the same reason, the dog bite epidemic must not focus on just one or two breeds and stop there. The war on this epidemic must be comprehensive.

Why Statistics Don't Always Work:

Consider five fatal attacks included in the CDC statistics.


A man was bitten in the forearm by a Pit bull. The bite was not serious but introduced into the wound was a virulent and fast spreading bacteria. The man died 4 days later from this virulent bacterial infection.

A teenage girl give birth to a infant, distraught and frightened, she tossed the hours-old infant into a neighboring-junk-strewn yard where two Pit bulls resided. The dogs killed the newborn.

A German shepherd mixed breed dog went into a bedroom, lifted a newborn out of a crib and carried the infant (by the head) into the living room  where the adults were seated.

A man restrains his girlfriend, while ordering his Pit bull to repeatedly attack her.  He is eventually convicted of murder and is serving a 20-year sentence.

An elderly man attempts to stop his German Shepherd dog from fence fighting with his neighbor's dog, the dog turns on his owner, severely mauling him, inflicting fatal head and neck wounds.

The CDC was right, in that five people died as a result of a dog bite. But were all these bites the result of aggression? Were they the same type or level of aggression? Which behaviors initiated the attack, human or canine? So the number of deaths by dogs (as per the CDC) cannot be used to define aggression, or the aggression of certain breeds, as aggression is not defined or qualified.