The Question Of Dogs, Off-leash Recreation, And Safety

A Review Of The Literature On Dog Bites

Linda S. Shore Ed.D

Introduction

The tragic dog mauling death of Diane Whipple was extensively reported by newspapers and television stations throughout the country. Details of the case were grotesque and sensational. Despite the fact that such violent attacks on people by dogs are exceedingly rare, media attention to the gruesome details of the mauling made the public extremely fearful of dogs. The following citations from the NPS ANPR document highlight the irrational fear that developed among citizens of San Francisco.

“…[In] January 2001, a 32-year old woman was mauled to death by a dog in San Francisco. Although this incident occurred outside the park boundaries, it underscored the danger of dogs in the local community to local users. Comments to the park opposing off-leash dogs have increased significantly since that time.” (National Park Service ANPR Document, 2002)

“The park has received complaints by park visitors, including minorities, seniors, and families with small children, alleging that off-leash dogs have precluded them from visiting the park for fear of being knocked over, attacked by dogs, or verbally abused by dog owners. Several recent letters involve visitors requesting permission or authorization to carry weapons (stun guns, pepper stray) for personal protection from dog attacks.” (National Park Service ANPR Document, 2002)

The ANPR document quotes from 2001 NPS Management Policies: “unless mandated by statute, the [National Park] Service will not allow visitors to conduct activities that create an unsafe or unhealthful environment for other visitors.” The question is, does off-leash dog walking really pose a threat to public safety? Although there is an elevated fear of dogs among the public due to the Diane Whipple case, sound public policy concerning the future of off-leash recreation in the National Parks cannot be dictated by irrationality. In light of the current hysteria surrounding dogs, it is prudent to study the research literature on the epidemiology of dog bites. It is especially important to review primary sources since opponents of off-leash dog areas sometimes interpret data in ways that were unintended by researchers.

To draw valid conclusions about the safety of off-leash recreation and make recommendations about how off-leash areas should be designed, the medical and veterinary research literature was reviewed. Large-scale surveys and seminal works were selected. The goal of the literature review was to answer the following questions: (1) How many bites or attacks occur in off-leash areas and/or dog parks? Is the threat of dog bites significant enough to prohibit off-leash recreation? (2) What is the typical relationship between victims and the dogs that bite them? Are victims typically dog owners and family members – or are people unknown to a dog at significant risk? (3) What are the actual reports of dog bite incidents in the GGNRA? Is the risk of injury from off-leash recreation high compared to other recreational activities allowed in the parks?

The Epidemiology Of Dog Bites

The Laboratory Centre for Disease Control, a branch of the Canadian national health agency, conducted one the most comprehensive surveys of injuries due to dog bites in the research literature (CHIRPP Injury Reports, 1998). Numerous researchers cite the work. In 1998, the authors of this study searched the national database of all reports of injuries throughout Canada during 1996. A total of 118,717 records were examined. All injuries caused by dogs were included in the analysis – a total of 1,237 records (representing 1% of all injuries reported that year). The findings can be summarized as follows: (1) Over 70% of all bites were sustained by children between 2 and 14 years. (2) Most dogs involved in bite incidents (65.2%) were either part of the family, part of the extended family, or were part of a friend’s family. (3) The majority of bite incidents (64.6%) occurred in someone’s home.

The authors of the Canadian study also examined the circumstances that were associated with dog bite injuries. The majority of bite victims had been interacting with the dog. These interactions included playing with a dog (17.5%), petting or feeding a dog (18.5%), hurting or provoking a dog (7.8%), and disciplining a dog (5.7%). In total, interacting with a dog provoked almost half (49.5%) of all dog bites. Of particular significance was the finding that only a very small percentage of bites occurred in public parks (1.1%) or sports and recreational areas (1.1%). In other words, bites occurring in locations similar to the National Parks (and parks within the GGNRA) accounted for 0.02% (2/100^th percent) of the 188,717 injuries that year – or about 41 cases.

The Canadian data are consistent with results of US surveys of dog bite injuries. According to the Centers For Disease Control (CDC), the median age of patients bitten by a dog is 15 years with the highest incidents reported among boys, ages 5 to 9 years. The CDC further reports that most bite incidents (61%) occur in a home and that over 75% of the dogs involved belong to the family or to a friend of the victim. When a child less than 4 years old is bitten, 90% of the incidents happen at home (see the NCIPC Bibliography of Articles on Dog Bites, http://www.cdc.gov/ncipc/duip/dogbites.htm).

While numerous researchers have studied a variety of factors and their correlation to dog bites, an extensive review examining the current research literature on dog bite injuries in the U.S. (JAVMA, 2001) found that there is actually very little data robust enough to positively identify factors with any predictive power. The authors of this review (The American Veterinary Medical Association Task Force On Canine Aggression) stated that the only conclusions that could be made from a critical examination of the literature was that children are at greater risk compared to adults and that family dogs are most likely to be involved in incidents. The task force review did not conclude anything at all about the safety of off-leash dog parks, nor did the authors describe any studies (robust or not) that examined this issue.

But when describing public safety risks associated with off-leash recreation, the ANPR document sites the same review article (JAVMA, 2001) and quotes the following to create an argument against off-leash dog parks:

“…according to the American Veterinary Medical Foundation Task Force on Canine Aggression: ‘although most dog bites occur on the property where the dog lives, unrestrained or free roaming dogs do pose a substantial threat to the public …”

(In JAVMA, 2001 and quoted in ANPR Document, 2002)

However, the Task Force On Canine Aggression is referring to stray dogs when it refers to “unrestrained or free roaming dogs.” Off-leash dogs that are supervised by their owners are not identified as a threat by the authors. In fact, immediately following the quotation above, the task force states that communities should impound these “free roaming dogs” when they are found and wait at least 5 days for owners to pick up their stray pets (JAVMA, 2001).

What kinds of dogs bite? Is dog breed a reliable predictor? While some studies have attempted to correlate dog breed with the propensity to bite, there is no agreement in the literature on which breeds are more likely to bite than others (JAVMA, 2001). However, research reported by Gershman, et. al (1994), who conducted a case controlled study of first-bite episodes reported to the Denver Municipal Animal Shelter during 1991, may shed some light the kinds of dogs likely to be involved in a bite incident. In this study, equal numbers of biting and non-biting dogs were matched and a variety of factors related to the characteristics of the dogs were compared. The researchers found that dogs without a license, without current vaccinations, who were not neutered, who were males, and who were left chained in backyards bit more frequently than did licensed dogs, those with current vaccinations, were neutered, who were female, and who were not left chained in backyards. The findings of Gershman, et.al are consistent with statistics reported by the Humane Society of the United States who state that there is a 8 in 10 chance that a biting dog will be male and a 6 in 10 chance that it will not have been neutered. These results imply that those dogs’ owners who act responsibly toward their pets (e.g. provide regular veterinary care, license their pets, neuter intact males, and do not leave dogs chained in backyards to become unsocialized and aggressive) are less likely to own a biting dog.

These results are also consistent with the recommendations of the San Francisco SPCA, who have asserted that well-socialized, healthy, and psychologically sound dogs are less likely to become aggressive. The SPCA has stated the following:

Dogs must have exercise, and that means regular off-leash play. Walks on a leash are nice, and dogs certainly enjoy getting out and sniffing around. But a walk on a leash is not exercise. Exercise means exertion. It means running off-leash and playing with other dogs. In an urban environment like San Francisco, most dog behavior problems can be traced to lack of exercise. Without sufficient exercise, dogs get bored and frustrated…They develop common behavior problems, like barking, chewing, jumpiness, and even aggression (our emphasis).

San Francisco SPCA, Benefits of Off-leash Recreation, 2002

Risks to the Public in the National Parks

To determine wherever or not to allow off-leash recreation on the basis of public safety, one needs to examine relative risk between off-leash dog walking and other forms of recreation allowed in the parks. Is the public at greater risk of an injury from a dog compared to the risk from other recreational activities that regularly take place in the GGNRA and other National Parks? This analysis is not meant to suggest that other forms of recreation should be forbidden by the NPS. Instead, this analysis is intended to examine the logic of banning off-leash recreation on the basis of protecting people from injury.

Quinlan, et al (1999) conducted one of the most comprehensive surveys of injuries in the U.S. The researchers conducted a study of hospital emergency departments and examined all persons receiving first-time treatment for an injury between May 1 through July 31, 1997. The frequency of all incidents documented by emergency departments is summarized in Table 1.

Table 1: Frequency of injuries reported by emergency departments in the US in 1991 (Quinlan, et.al, 1999)

Fall 24.1%

Struck by/against object 16.1%

Cut/Piece 11.7%

Motor vehicle/traffic 11.2%

Overexertion 10.9%

Natural environment 3.3%

Other (specified) 2.7%

Cycling 2.5%

Other transportation 2.0%

Fire/burn [1] 1.7%

Foreign body 1.7%

Machinery 1.6%

Dog Bite 1.3%

Poisoning 1.0%

Suffocation 0.5%

Other (unspecified) 0.5%

Pedestrian 0.2%

Note that dog bites accounted for only 1.3% of the most commonly reported injuries in the U.S. At least five of the injuries on the list are not only more common than dog bites, but can also be sustained by visitors to the National Parks. These are injuries caused by falling (24.1%), motor vehicles and traffic (11.2%) overexertion (10.9%), interacting with the natural environment (3.3%), cycling (2.5%), and using other forms of transportation (2%). One could argue that if off-leash dog walking is prohibited on the basis of protecting the public from injury, the NPS should also consider banning walking, hiking, all motor vehicle traffic, bicycling, recreational boating, horseback riding, hang gliding, and rock climbing. Combined, such activities account for over 54% of the injuries reported in the CDC database.

Some opponents to off-leash dog walking in the National Parks say they want to protect children from dog bites. While children are the most likely victims of a dog bite, how does the national frequency of dog bite injuries to children compare to other injuries – especially those that could be sustained in a national park? Quinlan, et al (1999) also indexed the leading causes of non-fatal injuries by age group. Dog bite injuries to children (ages 0 to 14 years) still ranked lower than injuries sustained by falls, the natural environment, motor vehicles, etc. Table 2 summarizes the results of this analysis.

Table 2: Leading causes of non-fatal injuries sorted by age groups (Quinlan, et.al., 1999)

Age	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10
0-4	Fall	Struck	Cut	NE	Poison	MV	Suff.	Dog B	OE	Burn
5-9	Fall	Struck	Cut	Bycl	MV	NE	OE	Dog B	Assault	FB
10-14	Struck	Fall	Cut	OE	Bycl	MV	Assault	Transp	NE	Dog B
15-19	Struck	MV	Fall	OE	Cut	Assault	?	NE	Bycl	Transp
20-24	Struck	MV	OE	Cut	Fall	Assault	Burn	FB	NE	Transp
25-34	OE	Struck	Fall	MV	Cut	Assault	MCH	NE	Transp	FB
35-44	Fall	OE	Struck	Cut	MV	Assault	NE	MCH	Transp	FB
44-54	Fall	Struck	MV	Cut	OE	NE	Assault	MCH	Transp	Burn
55-64	Fall	MV	Struck	Cut	OE	NE	Assault	FB	Transp	MCH
>65	Fall	Struck	MV	Cut	OE	NE	Transp	MCH	Assault	Dog B.

OE: Overexertion Bycl: Cycling, not related to MV FB: Foreign Body
NE: Natural Environment MV: Motor vehicle/traffic Suff: Suffocation

MCH: Machinery Transp: Other transportation ?: Unknown/Unspecified

It should be noted that a variety of other dangerous activities are sanctioned in the national parks: including rock climbing, wind surfing, water surfing, and hang gliding. Even game hunting with guns is permitted in at least 57 National Parks (over 2000 hunting permits are issued each year in the Amistad National Recreation Area in Texas alone). Within the GGNRA, even swimming and wading in the ocean represents a significant public safety hazard. Ocean Beach (part of the GGNRA in San Francisco) has some of the most dangerous surf in the world. Strong rip currents claimed the lives of 13 people from 1997 through 1998 (Lifeguard Effectiveness: Report From The Working Group, CDC Report, 2001), yet wading, surfing, and swimming are all allowed along the five-mile stretch of Ocean Beach.

Opponents to off-leash areas in the GGNRA also argue that the risk of dog walking is to the “innocent bystander”. However, this argument is not supported by research. Epidemiological studies of dog bite injuries indicate that the risk of injury is greatest to dog owners and minimal to the bystander – particularly if the bystander does not voluntarily provoke or interact with the dog (CHIRPP, 1998).

Actual Data on Dog Bites from the GGNRA

Data on dog-related incidents in the GGNRA provided by the NPS (1999 to 2001) were analyzed. Incidents described in these reports were categorized and entered into a spreadsheet. The analysis showed that off-leash recreation in the GGNRA is actually a very safe activity. In total, there were 1035 dog-related incidents requiring some kind of assistance from the NPS within the GGNRA. Dog related incidents reported include locating missing dogs (31), picking up stray dogs (60) and leash law violation warnings (388), Of the 1035 incidents in the three year period, only 84 involved a dog bite. Moreover, of these 84 dog bite reports, 37 incidents involved dogs biting other dogs. Only 38 incidents in the GGNRA over a 3-year period involve a dog biting a bystander and 5 incidents involved a bite to the dog’s owner or a friend. (See Chart 1).

According to the GGNRA (GGNRA NPS Web Site, Park Facts, 2002), the parks had 13,994,614 “recreational visits” during FY 2001. Therefore, given there were 38 bites to bystanders in about 42,000,000 recreational visits to the GGNRA in the 3-year period[2], we can estimate the chance that a dog will bite a stranger at 1 in 1.1 million visits. (Compare this to the risk of being struck by lightning in the US – which is 1 in 250,000). A summary of the risk of being bitten by a dog in the GGNRA is given in Table 3.

Table 3: Risk of Dog Bite in the GGNRA

Type of Bite	Risk*
Dog on Dog Dog on Owner or Friend Dog on Stranger	1 in 1,135,135 1 in 8,400,000 1 in 1,105,263

* Based on GGNRA incident reports from 1999 to 2001 and 13,944,614 visits to the GGNRA per year

Summary

The epidemiological research literature supports the following conclusions about injuries due to dog bites: most occur in the home, most victims are children, most dogs are well known to the victims, and most bites were provoked by some direct interaction with the dog. Relatively few incidents occur in parks or other recreational areas, to adults, to strangers, and to people who do not directly interact with a dog. Furthermore, factors that positively contribute to bite incidents relate far more to the characteristics of the owners than to the dogs themselves. Responsible dog owners (operationally defined by researchers as those that vaccinate, exercise, and socialize their pets) are far less likely to own biting dogs than irresponsible owners are. Ironically, it is responsible owners and well-behaved dogs that are penalized by restricting off-leash recreation. And by reducing opportunities for exercise and socialization, the risk of dog bites in the community at large may be substantially increased.

When GGNRA Incident Reports from 1999 through 2001 were examined, a total of 38 dog bites to bystanders were reported and 39 dog bites to other dogs. Given approximately 42 million recreational visits to the parks in 3 years, a simple calculation from GGNRA data showed that the chance of being bitten by an unknown dog within the GGNRA on any given visit is about 1 in 1.1 million. This finding suggests that the GGNRA parks may be even safer than the parks and recreational areas in Canada where researchers found that dog bites incidents in these locations accounted for 1/50^th percent of all injuries reported to emergency rooms in the country (CHIRPP Injury Reports, 1998).

The National Parks must insure public safety. No reasonable person would disagree with this. However, recreational activities all involve some risk of injury. Prohibiting a recreational activity based on public safety concerns – especially an extremely popular activity that has been ongoing in a park for decades – can only occur if the risk of injury goes far beyond what is tolerated for other activities. In the case of off-leash recreation, the risks to the public are infinitesimal. Ironically, off-leash dog walking appears to be one of the safest recreational activities occurring within the GGNRA. The Park Service might even consider highlighting this fact to help ease the fears of citizens still reeling from the horrific Diane Whipple dog mauling case.

If the Park Service wishes to reduce dog bite incidents even further in the GGNRA, it might also consider sponsoring education programs that teach children how to behave around dogs. Such programs could be beneficial since children are the most likely victims according to the research literature (although not at all evident in the GGNRA incident reports, where only 1 bite (“nip”) to a child was found in three years). Bite prevention programs for children have proven very successful in other communities. The National Park Service could solicit help from the dog advocacy groups and the SF SPCA in developing and implementing these kinds of workshops. The NPS could also build attractive playgrounds for toddlers and young children within each GGNRA park where dogs would be entirely forbidden – whether on or off-leash. Finally, the GGNRA could host training sessions for dog owners who want to learn more about identifying risky situations and avoiding bite incidents.

References

ANPR Document, 2002, National Park Service,

Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP), Health Canada, Injuries associated with dog bites and dog attacks. (1998). Summary data for 1996, all ages. URL: www.hc-sc.gc.ca/hpb/lcdc/brch/injury/dogbit_e.html

Gershman, K.A., Sacks,J.J. and Wright, J.C. (1994). Which Dogs Bite? A Case Controlled Study Of Risk Factors, Pediatrics. Vol. 93 No 6. Pp. 913-917

GGNRA Dog Incident Reports, 1999 to 2001. Excel spreadsheet.

Lifeguard Effectiveness: Report From The Working Group, Centers for Disease Control Report, 2001.

Task Force On Canine Aggression, American Veterinary Medical Association, A community approach to dog bite prevention. In JAVMA,(June 1, 2001), Vol. 281, No. 11. Pp. 1732 -1746.

Quinlan, K.P., Thompson, M.P., Annest, J.L., Ryan, G., Kessler, E.P., McDonald, A.K., Injury Prevention. (November, 1999) Annals of Emergency Medicine. Vol. 34, No. 5.

San Francisco SPCA, Benefits of Off-leash Recreation, Internet Report. 2002

Vet Med Today: Special Report, JAVMA, (June, 2001) Vol. 218, No. 12, pg. 1994 - 2001

Chart 1: Summary of Dog Bite Incidents in the GGNRA from 1999 to 2001

Dog Bites Dog	37
Dog Bites Person	38
Dog Bites Owner	4
Dog Bites Friend of Owner	1
Dog Bites Horse	4
Unspecified (not described)	2
TOTAL	84

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[1] Despite the National Park Service’s policy to set “control fires” in its parks (e.g. Los Alamos, Yellowstone), we do not include injuries from fire and burning in this analysis of risks to visitors in the parks.

[2] This total is conservative. The ANPR document claims 17 million visitors to the GGNRA parks each year for a total of 51 million visitors in 3 years.