National data and trends
The rates of dog bite-related injuries by age and sex for the period 2005-2018 are presented in Table 1. Consistent with previous research findings, the data show that age is strongly related to the rate of dog bite injuries (Gilchrist et al., 2008; Weiss et al., 1998; Hoff et al., 2005; Quirk, 2012; Holtzer et al., 2019). The modal category is the age group 5 to 9, followed by the age groups 0 to 4 and 10 to 14. From the age group 15 to 19 and older, injuries taper off considerably. The data also reveal that gender is associated with dog bite injuries. Through the age of 14, the rate of males exceeds that of females by a wide margin. For the older age groups, the disparity between the gender groups narrows.
Table 1 Estimated Rates of Dog Bite Injuries Treated in an Emergency Department by Gender and Age Group in the United States: 2005-2018
|
Both Sexes
|
Males
|
Females
|
Age Group
|
Ratea (95% CI)
|
Rate (95% CI)
|
Rate (95% CI)
|
0 to 4
|
183.9 (156.4-211.5)
n = 515,159
|
200.7 (169.3-232.0)
n = 287,227
|
166.3 (141.9-1908.)
n = 227,784
|
5 to 9
|
202.9 ( 176.2-229.7)
n = 573,130
|
228.4 (198.1-258.7)
n = 329,453
|
176.4 (151.6-201.1)
n = 243,655
|
10 to 14
|
155.4 (133.8-177.0)
n = 451,812
|
184.4 (158.4-210.5)
n = 274,028
|
125.1 (107.2-143.0)
n = 177,784
|
15 to 19
|
111.4 (96.2-126.5)
n = 335,729
|
115.4 (99.8-131.1)
n = 178,420
|
107.1 (91.1-123.0)
n = 157,309
|
20 to 44
|
108.9 (94.6-123.2)
n = 1,607,452
|
110.8 (97.0-124.7)
n = 823,362
|
106.9 (91.6-122.2)
n = 784,090
|
45 to 64
|
85.4 (72.0-98.9)
n = 968,890
|
80.9 (69.0-92.8)
n= 447,302
|
89.8 (74.4-105.2)
n = 521,567
|
65 and over
|
58.7 (48.6-68.8)
n = 355,358
|
58.2 (47.3-69.1)
n= 153,379
|
59.0 (49.2-68.9)
n= 201,979
|
a Rates are calculated per 100,000 population
Table 2 displays the annual estimated frequency and rates of dog bite injuries resulting in an ED visit in the United States from 2005 to 2018. Figure 1 graphs the estimated annual rates. The data show that the rates of injuries tended to increase until 2012 and then underwent an overall decline thereafter (P = .046 for the curvilinear relationship).
Table 2 Annual Estimated Frequency and Rates of ED Visits Due to Dog Bite Injuries in the United States, 2005-2018
Year
|
Frequency
|
Ratea
|
2005
|
321,694
|
108.9
|
2006
|
310,687
|
104.1
|
2007
|
312,231
|
103.7
|
2008
|
333,235
|
109.6
|
2009
|
337,526
|
110.0
|
2010
|
346,331
|
112.2
|
2011
|
359,972
|
115.5
|
2012
|
362,724
|
109.8
|
2013
|
346,925
|
109.8
|
2014
|
353,954
|
111.2
|
2015
|
347,952
|
108.5
|
2016
|
370,187
|
114.6
|
2017
|
354,154
|
108.9
|
2018
|
349,961
|
107.0
|
a Rates are calculated per 100,000 population
Noteworthy is that the relationship between the incidence of dog bite injuries varies by age group over time. Figure 2 exhibits the rates of dog bite injuries resulting in a visit to an ED by age group during the time period 2005 to 2018. Paralleling the overall trend for the country as a whole, the rates of the two youngest age groups (0 to 9, 10-19) initially increase up to 2012 and then undergo a steep decline. The opposite pattern prevails for the two older age groups (20-44, 45 plus). Here the rates of these two groups increase over the course of the 13 year span.
New York State and New York City: individual-level effects
The results of the negative binomial regression analysis examining the simultaneous effects of time and key demographic variables on the incidence of dog bites treated in an ED are displayed in Table 3. The analysis is confined to two geographic locations – New York City and New York State excluding New York City. The predictor variables consist of year, year squared, place of residence, gender, age group, and the racial-ethnic background of patients.
Table 3 Negative Binomial Regression Estimates of Injuries Due to Dog Bites,
New York State and New York City, 2005-2018
Variable
|
Exp(b)
|
95% CI
|
|
|
|
Time
|
|
|
Year
|
1.086**
|
1.029 – 1.145
|
Year Squared
|
0.995**
|
0.991 – 0.998
|
Place
|
|
|
New York City
|
0.714***
|
0.644 – 0.791
|
New York State minus New York City
|
(ref. category)
|
|
Gender
|
|
|
Female
|
0.895*
|
0.810 – 0.990
|
Male
|
(ref. category)
|
|
Age category
|
|
|
0 to 4
|
2.034***
|
1.681 – 2.462
|
5 to 9
|
2.821***
|
2.332 – 3.413
|
10 to 14
|
2.374***
|
1.961 – 2.873
|
15 to 19
|
1.991***
|
1.645 – 2.410
|
20 to 44
|
1.721***
|
1.424 – 2.080
|
45 to 64
|
1.501***
|
1.242 – 1.813
|
65 and older
|
(ref. category)
|
|
Race/Ethnicity
|
|
|
Non-Hispanic White
|
0.950
|
0.824 – 1.094
|
Non-Hispanic Black
|
1.060
|
0.919 – 1.221
|
Non-Hispanic Asian
|
0.460***
|
0.398 – 0.532
|
Hispanic
|
(ref. category)
|
|
|
|
|
Significance level: * p < 0.05
|
|
|
**p <0.01
|
|
|
***p < 0.001
|
|
|
The effects of year and the multiplicative term of year squared are both significant. A graphic display of these terms indicates that from 2005 to 2012 the frequency of dog bite injuries increased and then from 2013 to 2018 decreased, controlling for the other variables in the analysis. The same general pattern emerges if the injury rate of just individuals who were admitted as inpatients serves as the dependent variable. Both trends mirror the results observed at the national level.
Inspection of Table 3 indicates that residents of New York State outside of New York City are more likely to be treated in an ED for a dog bite than residents of the city. This finding reflects the greater prevalence of dog bite injuries in less densely populated areas. Coinciding with the findings from the national data discussed above, the table also shows that there is a significant gender gap in the incidence of dog-related injuries. Males are 1.12 times more likely to visit an ED due to a dog bite than females.
As expected, age is a major determinant of the risk of injury from a dog bite. Compared with patients who are 65 and older (the reference category), patients aged 5 to 9 are 2.7 times more likely to incur a dog bite injury and patients aged 10 to 14 are 2.3 more likely to sustain an injury. Individuals in the other age categories (0 to 4, 15 to 19, 20 to 44, and 45 to 64) are also significantly more likely to be injured by a dog bite than those in the reference category.
Finally, the data reveal that non-Hispanic Asians are considerably less likely to be treated in an ED for a dog bite than Hispanics (the reference category). The odds ratios for the other racial-ethnic groups are not statistically significant.
Socio-demographic correlates of dog bite injury rate in New York State counties and New York City neighborhoods
Table 4 displays the relationship between key socio-demographic variables and the rate of injuries due to dog bites at both the county level in New York State and the neighborhood level in New York City. The data indicate that the rate of injuries due to dog bites is negatively associated with population density. This relationship between injury rate and population density is most pronounced at the county level. The data also show that at the county level, the injury rate is positively associated with the percent of the population which is non-Hispanic white, reflecting the relationship between urbanicity and racial-ethnic composition. Significantly, at both the county and UHF levels, there is a strong negative association between the injury rate and a number of economic variables. Injuries are more prevalent in counties or neighborhoods with lower median family income, per capita income, or proportion of the population which is not college-educated.
Table 4 Correlations Between Selected Demographic Characteristics and Dog Bite Injury Rate in New York State Counties and in New York City United Health Fund Districts: 2018
New York City
New York State United Health
Counties Fund Districts
Correlation Correlation
Coefficient Coefficient
Demographic Characteristic (N = 62) (N = 42)
Population density (per sq. mile)
|
-0.35**
|
-0.25
|
Percent non-Hispanic white
|
0.51***
|
-0.26
|
Percent non-Hispanic black
|
-0.50***
|
0.00
|
Percent non-Hispanic Asian
|
-0.46***
|
-0.11
|
Percent Hispanic
|
-0.42**
|
0.42**
|
Median family incomea
|
-0.47***
|
-0.32*
|
Per capita incomea
|
-0.43**
|
-0.34*
|
Percent of families below the poverty level
|
0.11
|
.48**
|
Percent of population 25 years of age and older who have a B.A. degree or more
|
-0.51***
|
-0.41**
|
Percent of population with no health insurance
|
0.07
|
0.26
|
Percent of insured population with public health insurance
|
0.35**
|
0.33*
|
aMedian family income and per capita income were calculated by computing the median values of these two variables for all zip codes within each UHF district.
Significance level: *p < .05
** p < 0.01
*** p < 0.001
Table 5 presents the results of an analysis performed on self-reported incidents of dog bites in New York City’s United Health Fund districts for the years 2015 to 2017.
The table shows the socio-demographic correlates of both the percent of dogs which were spayed/neutered and the percent of dogs which were pit bulls in the 42 UHF districts. Of the breeds identified in the data set (84.6%), pit bulls were the most numerous (33.6%), followed in order by Shih Tzu (5.3%), Chihuahua (5.2%), German Shepherd (4.1%), and Yorkshire Terrier (3.1%). This finding is consistent with previous research showing that pit bulls are responsible for more bites than any other dog breed (McReynolds, 2019). Of the self-reported cases 29.1% were classified as spayed or neutered. The results reveal that poorer neighborhoods were associated with a higher proportion of dogs which had not been spayed/neutered and also a higher proportion of dogs which were pit bulls.
Table 5 Correlations Between Selected Demographic Characteristics and (1) Percent of Dogs Who are Neutered/Spayed and (2) Percent of Dogs Which are Pit Bulls in New York City United Health Fund Districts: 2015-2017
Percent of
Dogs who Percent of
are Neutered/ Dogs Which
Spayed are Pit Bulls
Correlation Correlation
Coefficient Coefficient
Demographic Characteristic (N = 62) (N = 42)
Population density (per sq. mile)
|
-0.01
|
-0.19
|
Percent non-Hispanic white
|
0.82***
|
-0.72***
|
Percent non-Hispanic black
|
-0.57***
|
0.75***
|
Percent non-Hispanic Asian
|
0.35*
|
-0.58***
|
Percent Hispanic
|
-0.64***
|
0.45**
|
Median family incomea
|
0.64***
|
-0.61***
|
Per capita incomea
|
0.57**
|
-0.63***
|
Percent of families below the poverty level
|
-0.72***
|
.58***
|
Percent of population 25 years of age and older who have a B.A. degree or more
|
0.67***
|
-0.67***
|
Percent of population with no health insurance
|
-0.48**
|
0.25
|
Percent of insured population with public health insurance
|
- 0.73**
|
0.58***
|
aMedian family income and per capita income were calculated by computing the median values of these two variables for all zip codes within each UHF district.
Significance level: *p < .05
** p < 0.01
*** p < 0.001
Spatial distribution of dog bites in New York City’s neighborhoods
Coinciding with expectations, the rates of dog-bite injuries are not uniformly distributed across the UHF districts. A choropleth map of the rates shows that the Hunts Point-Mott Haven neighborhood in the Bronx, East Harlem neighborhood in Manhattan, the Sunset Park neighborhood in Brooklyn, and the Port Richard and Stapleton-St. George neighborhoods in Staten Island have notably higher rates than other UHF districts (see Figure 3). The Moran’s I Index yields a value of .356 (p < .001), indicating a pattern of spatial clustering .
Profile of dog owners in the United States
Surveys of dog owners during the last decade reveal significant changes in their demographic characteristics (Table 6). The data in the table shows that the age distribution of dog owners has skewed upwards in the past decade. In 2008, 26.1 percent of dog owners fell into the age category of 55 to 74; by 2018, the number of owners in this age category rose to 31.5 percent. In this same 10-year span of time, dog owners were also more likely to be Hispanic, reside in larger metropolitan areas, and have higher levels of education. Another noteworthy change is the reduction in the number of younger children living in the household. The number of children in each of the age brackets under 6, 6 to 11, and 12 to 17 all dropped in the years from 2008 to 2018.
Table 6 Profile of Dog Owners in the United States: 2008-2018
Year
Percent
Characteristic 2008 2018 Change
Age Group
|
|
|
|
18-34
|
23.2%
|
24.1%
|
+0.9
|
35-54
|
45.1%
|
39.3%
|
-5.8
|
55-74
|
26.1%
|
31.5 %
|
+5.4
|
75 and over
|
5.6%
|
5.1%
|
-0.5
|
Total %
|
100.0%
|
100.0%
|
|
|
|
|
|
Race-Ethnicity
|
|
|
|
White non-Hispanic
|
81.4%
|
75.5%
|
-5.9
|
Black non-Hispanic
|
4.9%
|
4.6%
|
-0.3
|
Asian non-Hispanic
|
2.1%
|
2.3%
|
+0.2
|
Hispanic
|
9.5%
|
15.1%
|
+5.6
|
Total %
|
100.0%
|
100.0%
|
|
|
|
|
|
Location
|
|
|
|
Top 25 Metro Areas
|
42.3%
|
45.8%
|
+3.5
|
Top 26-100 Metro Areas
|
40.9%
|
42.8%
|
+1.9
|
Not Top 100 Metro Areas
|
16.8 %
|
11.4%
|
-5.4
|
Total %
|
100.0%
|
100.0%
|
|
|
|
|
|
Education
|
|
|
|
Non High School Graduate
|
12.5%
|
5.9%
|
-6.6
|
High School Graduate Only
|
28.7%
|
28.7%
|
0.0
|
Undergraduate College Degree Only
|
16.7%
|
20.7%
|
+4.0
|
Graduate Degree
|
7.3%
|
9.4%
|
+2.1
|
Total %
|
100.0%
|
100.0%
|
|
|
|
|
|
Age of children in household
|
|
|
|
Under 6
|
14.0
|
12.8
|
-1.2
|
6 to11
|
17.0
|
13.7
|
-3.3
|
12 to 17
|
15.8
|
12.8
|
-3.0
|
|
|
|
|
Total Number of Dog Owner
Households (000s)
|
42010
|
46962
|
+4952
|