Marty
06-07-2008, 07:24 PM
How many times have we heard someone in the media spotlight making inflammatory statements about dog bites statistics in an interview, without ever disclosing their source? Even when the comments seem highly suspicious, few people question their validity. (Especially editors and news directors it would seem.) Researching this subject on the Internet has uncovered some enlightening information.
According to CBS News, the Early Show (2002) “About 4.7 million people are bitten by dogs each year. One million of those need medical attention. About 750,000 children are bitten by dogs each year; in most cases, these bites are from “familiar dogs” – not strays. Approximately 12 people die each year from dog bites.” When I tried to cross-reference these statistics I encountered a problem that was to become typical. The “4.7 million” appears to come from a JAVMA article evaluating data from 1994, almost six years earlier!
Most of the studies and references that I found gave a list of resources, but no footnotes as to which source any given statistic came from and many were significantly out of date. This makes it difficult to guarantee the accuracy of many of the statistics I read. However, the motivation of the source must be taken into consideration as well as the fact that many sources derive their data from news reports instead of county health records. My personal experience has shown that only about half of the dog bites reported as “pit bulls”, actually are, as many mixed breed dogs are called “pit bulls” unless proven other wise. Also, many studies quoted each other’s data as a premise for their own. Since there does seem to be a consensus of opinion on some of it, I will repeat only what I believe to be credible.
“Fatal Dog Attacks in the US, from 1965-2001”, analyzed 431 cases over 35 years and:
10% involved leashed dogs or misc. circumstances
17% resulted from attacks by dogs roaming off their owners’ property
73% involved dogs within the boundaries of the owners’ property
(25% chained dogs, 25% dogs in yard, and 23% dogs inside the home)
Surprisingly, it made no difference whether or not the dogs were chained as 75% involved in fatalities were not chained, and yet this has been frequently cited by animal rights proponents to cause aggression. (At least a chained dog can’t chase you!) Currently, the AVMA has no official position on tethering and a 2001 study conducted at Cornell University comparing tethered dogs to those in pens stated “the behavior of the dogs in this study did not indicate an improvement in welfare in pens”. No other controlled study has ever been conducted on this subject.
The oft quoted statistic that chained dogs are 2.8 times more likely to bite is, based on my research, a specious assumption. Derived from “Which dogs bite? A case-control study of risk factors” (Pediatrics 1994) which uses only 178 hand picked cases out of 991 reported bites, and there are no statistics as to how many dogs within Denver Metro Animal Services jurisdiction were tethered full time, part time or not at all in the total dog population. In regards to contributing factors, especially tethering, I would have to say that this study has no scientific merit whatsoever because, as one of my peers stated:
“The study uses one of the most UN-reliable methods there is: Survey. Worse, sampler bias can be introduced to the study because samplers know which are control dogs and which are study dogs. They admit that Chows and GSDs are most common, and then announce that these two breeds are responsible for most of the bites! Worse, they rely on the owner's id of the breed, even in mixed breeds. …The only way to determine if chaining will cause aggressive behavior is to have a control and a study group, both of which receive equal amounts of attention, food, time, and exercise, and have one group "tethered" and the other either penned or crated. And that would only answer the question as to whether the chaining method chosen caused aggression: it would not answer questions related to longer or shorter chains, less or more attention, etc.”
Additionally, the study specifically states that "Bite report forms indicated where 101 {...out of 991} (56.7%) of the incidents. Of these 51 (51.5%) took place on the sidewalk, street, alley or playground...;30 (29.7%)in the owner's yard;14(13.9%) in the owner's house; and 4 (4%) in the victims yard." And data on whether the bites were PROVOKED was NOT systematically reported.
Further, it goes on to state: "Biting dogs were significantly more likely to reside in homes with one or more children (less than age ten) and to be chained while in the yard. Of the 83 dogs chained while in the yard (cases plus controls), 44 (53%) had growled or snapped at visitors to the house. (Maybe that’s why they were chained?) This behavior was also reported, however, of 116 (44%) of 263 dogs not chained while in the yard". It seems to me that given the ridiculously small sampling (178 cases out of a national dog population that easily exceeds 60 million), lack of both numerator and denominator for containment figures, failure to separate tethering from the presence of children as contributing factors and control group methodology, I personally feel it would be a far more adequate conclusion that the contributing factor in tethered dog bites is unattended children.
Fatal Dog Attacks appears to support my assumption by stating that:
68% of fatalities were inflicted by a single dog
79% of victims were children under the age of 12
09% were ages 13-64 years old
12% were elderly, 65-94 years old
Children under the age of one year accounted for the highest number of fatalities, at 19%. Over 95% of these deaths occurred when an infant was left unsupervised!
The group with the second highest number of fatalities was 2 year olds, at 11%. Over 87% of these fatalities occurred when the child was left unsupervised!
Boys, ages 1-12 years old were 2.5 times more likely to be the victims of a fatal attack than girls of the same age.
Of the 28 single dogs responsible for a fatal attack between 200-2001, 26 were males and only 2 were females.
The Fatal Dog Attacks study concludes, “While at times informative, statistics on fatal dog attacks can also be misleading. For example, a number of cases where a Pit Bull, Rottweiler or German Shepherd Dog were counted as causing a human fatality, in reality the direct result was from gross human negligence or criminal intent”. (Hmmm…you don’t say?)
The American Veterinary Medical Association publication Vet Med Today: Special Report, also compared DBRF (dog bite related fatality) statistics, collected from 1971-1998. Their findings were similar but the percentage of chained dogs dropped significantly. During 1997 and 1998, a total of 27 DBRF were reported. (NCRF reported a total of 29 fatal bites for the same time period.)
19% resulted from attacks by dogs roaming off their owners’ property
67% involved unrestrained dogs on the owner’ property
11% involved restrained dogs on the owners’ property (chained?)
4% involved restrained dogs off the owners’ property
67% were single dog attacks
“Some breed information was reported for all 27 attacks. As in recent years, Rottweilers were the most commonly reported breed involved in fatal attacks, followed by pit bull-type dogs.” (What was the criteria to determine ”type” when even ”pit bull” is a slang term that may include several breeds?) “The denominator of a dog breed specific human DBRF rate requires reliable breed-specific population data. Unfortunately, such data are not currently available.” And, “Finally, it is imperative to keep in mind that even if breed-specific bite rates could be accurately calculated, they do not factor in owner related issues.” (Ninety cases were excluded from the overall study because the breed involved could not even be determined.)
They also mention a study by Pickney and Kennedy (Pediatrics 1982) listing DBRF from May of 1975 through April of 1980 which lists German Shepherd Dogs as the #1 killer for that time period, Husky type dog second and Saint Bernard third. “Indeed since 1975, dogs belonging to more than 30 breeds have been responsible for fatal attacks on people, including Dachshunds, a Yorkshire Terrier, and a Labrador Retriever.”
According to CBS News, the Early Show (2002) “About 4.7 million people are bitten by dogs each year. One million of those need medical attention. About 750,000 children are bitten by dogs each year; in most cases, these bites are from “familiar dogs” – not strays. Approximately 12 people die each year from dog bites.” When I tried to cross-reference these statistics I encountered a problem that was to become typical. The “4.7 million” appears to come from a JAVMA article evaluating data from 1994, almost six years earlier!
Most of the studies and references that I found gave a list of resources, but no footnotes as to which source any given statistic came from and many were significantly out of date. This makes it difficult to guarantee the accuracy of many of the statistics I read. However, the motivation of the source must be taken into consideration as well as the fact that many sources derive their data from news reports instead of county health records. My personal experience has shown that only about half of the dog bites reported as “pit bulls”, actually are, as many mixed breed dogs are called “pit bulls” unless proven other wise. Also, many studies quoted each other’s data as a premise for their own. Since there does seem to be a consensus of opinion on some of it, I will repeat only what I believe to be credible.
“Fatal Dog Attacks in the US, from 1965-2001”, analyzed 431 cases over 35 years and:
10% involved leashed dogs or misc. circumstances
17% resulted from attacks by dogs roaming off their owners’ property
73% involved dogs within the boundaries of the owners’ property
(25% chained dogs, 25% dogs in yard, and 23% dogs inside the home)
Surprisingly, it made no difference whether or not the dogs were chained as 75% involved in fatalities were not chained, and yet this has been frequently cited by animal rights proponents to cause aggression. (At least a chained dog can’t chase you!) Currently, the AVMA has no official position on tethering and a 2001 study conducted at Cornell University comparing tethered dogs to those in pens stated “the behavior of the dogs in this study did not indicate an improvement in welfare in pens”. No other controlled study has ever been conducted on this subject.
The oft quoted statistic that chained dogs are 2.8 times more likely to bite is, based on my research, a specious assumption. Derived from “Which dogs bite? A case-control study of risk factors” (Pediatrics 1994) which uses only 178 hand picked cases out of 991 reported bites, and there are no statistics as to how many dogs within Denver Metro Animal Services jurisdiction were tethered full time, part time or not at all in the total dog population. In regards to contributing factors, especially tethering, I would have to say that this study has no scientific merit whatsoever because, as one of my peers stated:
“The study uses one of the most UN-reliable methods there is: Survey. Worse, sampler bias can be introduced to the study because samplers know which are control dogs and which are study dogs. They admit that Chows and GSDs are most common, and then announce that these two breeds are responsible for most of the bites! Worse, they rely on the owner's id of the breed, even in mixed breeds. …The only way to determine if chaining will cause aggressive behavior is to have a control and a study group, both of which receive equal amounts of attention, food, time, and exercise, and have one group "tethered" and the other either penned or crated. And that would only answer the question as to whether the chaining method chosen caused aggression: it would not answer questions related to longer or shorter chains, less or more attention, etc.”
Additionally, the study specifically states that "Bite report forms indicated where 101 {...out of 991} (56.7%) of the incidents. Of these 51 (51.5%) took place on the sidewalk, street, alley or playground...;30 (29.7%)in the owner's yard;14(13.9%) in the owner's house; and 4 (4%) in the victims yard." And data on whether the bites were PROVOKED was NOT systematically reported.
Further, it goes on to state: "Biting dogs were significantly more likely to reside in homes with one or more children (less than age ten) and to be chained while in the yard. Of the 83 dogs chained while in the yard (cases plus controls), 44 (53%) had growled or snapped at visitors to the house. (Maybe that’s why they were chained?) This behavior was also reported, however, of 116 (44%) of 263 dogs not chained while in the yard". It seems to me that given the ridiculously small sampling (178 cases out of a national dog population that easily exceeds 60 million), lack of both numerator and denominator for containment figures, failure to separate tethering from the presence of children as contributing factors and control group methodology, I personally feel it would be a far more adequate conclusion that the contributing factor in tethered dog bites is unattended children.
Fatal Dog Attacks appears to support my assumption by stating that:
68% of fatalities were inflicted by a single dog
79% of victims were children under the age of 12
09% were ages 13-64 years old
12% were elderly, 65-94 years old
Children under the age of one year accounted for the highest number of fatalities, at 19%. Over 95% of these deaths occurred when an infant was left unsupervised!
The group with the second highest number of fatalities was 2 year olds, at 11%. Over 87% of these fatalities occurred when the child was left unsupervised!
Boys, ages 1-12 years old were 2.5 times more likely to be the victims of a fatal attack than girls of the same age.
Of the 28 single dogs responsible for a fatal attack between 200-2001, 26 were males and only 2 were females.
The Fatal Dog Attacks study concludes, “While at times informative, statistics on fatal dog attacks can also be misleading. For example, a number of cases where a Pit Bull, Rottweiler or German Shepherd Dog were counted as causing a human fatality, in reality the direct result was from gross human negligence or criminal intent”. (Hmmm…you don’t say?)
The American Veterinary Medical Association publication Vet Med Today: Special Report, also compared DBRF (dog bite related fatality) statistics, collected from 1971-1998. Their findings were similar but the percentage of chained dogs dropped significantly. During 1997 and 1998, a total of 27 DBRF were reported. (NCRF reported a total of 29 fatal bites for the same time period.)
19% resulted from attacks by dogs roaming off their owners’ property
67% involved unrestrained dogs on the owner’ property
11% involved restrained dogs on the owners’ property (chained?)
4% involved restrained dogs off the owners’ property
67% were single dog attacks
“Some breed information was reported for all 27 attacks. As in recent years, Rottweilers were the most commonly reported breed involved in fatal attacks, followed by pit bull-type dogs.” (What was the criteria to determine ”type” when even ”pit bull” is a slang term that may include several breeds?) “The denominator of a dog breed specific human DBRF rate requires reliable breed-specific population data. Unfortunately, such data are not currently available.” And, “Finally, it is imperative to keep in mind that even if breed-specific bite rates could be accurately calculated, they do not factor in owner related issues.” (Ninety cases were excluded from the overall study because the breed involved could not even be determined.)
They also mention a study by Pickney and Kennedy (Pediatrics 1982) listing DBRF from May of 1975 through April of 1980 which lists German Shepherd Dogs as the #1 killer for that time period, Husky type dog second and Saint Bernard third. “Indeed since 1975, dogs belonging to more than 30 breeds have been responsible for fatal attacks on people, including Dachshunds, a Yorkshire Terrier, and a Labrador Retriever.”