An Estimate of the Number of Dogs in US Shelters. Kimberly A. Woodruff, DVM, MS, DACVPM David R. Smith, DVM, PhD, DACVPM (Epi)

Size: px

Start display at page:

Download "An Estimate of the Number of Dogs in US Shelters. Kimberly A. Woodruff, DVM, MS, DACVPM David R. Smith, DVM, PhD, DACVPM (Epi)"

Cecilia Veronica Williams
6 years ago
Views:

1 An Estimate of the Number of Dogs in US Shelters Kimberly A. Woodruff, DVM, MS, DACVPM David R. Smith, DVM, PhD, DACVPM (Epi)

2 Currently. No governing body for shelter medicine No national list/registration of animal humane organizations No national registration/census of shelter animals Difficult to estimate total number of dogs in shelters

3 Objectives Estimate total number of shelters in the United States Brick and mortar Intake/adopt out dogs Estimate number of dogs entering US shelters annually and their outcome Returned to owner Adopted Transferred Euthanized Identify characteristics of US shelters that modify dog movement.

4 Materials and Methods Initial list of 10,890 animal shelters AND rescue organizations in the United States For inclusion Must accept dogs Must adopt dogs to the public Brick and mortar

5 Materials and Methods

6 Materials and Methods Additional shelters removed for: not being an animal shelter not a shelter for dogs not adopting dogs to public Duplicates Final Survey Frame: 2,862 Shelters from 49 states

throughout July, 2016 8 attempts per shelter

7 Materials and Methods Telephone survey Attempt to contact each of 2, 862 Calls made throughout July, attempts per shelter before number was retired 413 complete surveys (14.4%)

8 Statistical Methods Factors associated with number of dogs entering a shelter were tested using multivariable linear regression with shelter as the unit of investigation Proc Mixed SAS Factors associated with the probability for a dog in a shelter to be adopted, transferred, returned to owner or euthanized were tested using multivariable logistic regression with shelter as a cluster effect Proc GenMod SAS (generalized estimating equation)

9 What is the total number of dog shelters in the United States? This sampling frame (like others) is likely an subset of the true number of dog shelters in the US If we knew the total number of shelters in the US, we could use the survey results to estimate the total number of dogs in shelters and other statistics A novel approach to this problem is capturerecapture methodology

10 Capture-recapture methodology Used by wildlife researchers to estimate the number of animals in a population Compare shelters in our frame (capture) to other frames (recapture) E.g. the proportion of shelters from Mississippi in our frame and also found in an independent frame of Mississippi shelters

11 Capture-recapture methodology The simplest method for estimating population size is the Lincoln-Petersen method. The basic method involves a single marking and a single recapture episode. If we mark a sample of animals, M and capture a sample of animals, C, containing R marked individuals, we estimate the size of the population at the time of the original marking, N, as: N=MC/R

12 Capture-recapture methodology We know M (2,862). If we can estimate C/R, then we can calculate the total number of shelters. C = the total number of shelters in other lists FL, MI, MS, MA, SC R = the number of repeats Clopper-Pearson 95% CI around R/C N=MC/R

13 Relative Frequency 25.0% 20.0% 15.0% 10.0% Number of dogs entering the shelter Mean: Median: 500 Max: 5500 Min: % 0.0% Number

14 Number of Dogs Entering Shelters Variable Estimate Standard error Intercept Funding Source P-Value Mixed <.0001 Municipal Private 0 Region Midwest <.001 Accepts Surrender Northeast Southeast Southwest West 0 No Yes 0

15 Adoption Transfer Return to Owner Euthanize

16 Adoption

17 Number of dogs adopted Relative Frequency 50.0% 45.0% 40.0% 35.0% 30.0% 25.0% 20.0% 15.0% 10.0% 5.0% 0.0% Mean: Median: 225 Max: 2750 Min: Number

18 Dogs Exiting Facilities through Adoption Variable Estimate Standard Error 95% Confidence Limits P-Value Intercept Funding Source Admission Type Mixed <.0001 Municipal Private Limited admission Open admission

19 Probability for a Shelter to Adopt a Dog Probability Funding Source Municipal: OR: 0.59 ( ) Mixed: OR: 0.30 (0.23, 0.39) Private: Referent 0 Mixed Municipal Private Funding source

20 Probability for a Shelter to Adopt a Dog Admission Type Limited admission: OR: 2.75 (1.46, 5.20) Open admission: Referent 0.6 Probability No Stray Admission Yes

21 Transfer

22 Relative Frequency 70.0% 60.0% 50.0% 40.0% 30.0% 20.0% Number of dogs transferred Mean: 110 Median: 25 Max:1702 Min: % 0.0% Number

23 Transfer Analysis of GEE Parameter Estimates Variable Estimate Standard Error 95% Confidence Limits Intercept Funding source P-value Mixed Municipal Private Region Midwest <.001 Admission Type Northeast Southeast Southwest West Limited admission Open Admission

24 Probability for a Shelter to Transfer a Dog Funding Source Mixed: OR: 1.59 (0.20, 2.56) Municipal: OF: 2.07 (1.39, 3.1) Private: Referent Probability Mixed Municipal Private Funding Source

25 Probability Probability for a Shelter to Transfer a Dog Region MW NE SE SW W United States Region Midwest: OR: 1.29 (0.77, 2.17) Northeast: OR: 0.20 (0.09, 0.46) Southeast: OR: 1.54 (0.91, 2.60) Southwest: OR: 1.22 (0.65, 2.30) West: Referent

26 Probability for a Shelter to Transfer a Dog 0.12 Admission Type Probability Limited Admission: OR: 0.26 (0.09, 0.76) Open Admission: referent No Stray Admission Yes

27 Return to Owner

28 Number of Dogs Returned to Owner 70.0% 60.0% Number of dogs returned to owner Relative Frequency 50.0% 40.0% 30.0% 20.0% 10.0% 0.0% Number

29 Dogs returned to owner Variable Estimate Standard Error 95% Confidence Limit P-Value Intercept Funding Source Mixed < Municipal Private Region Midwest < Admission Type Shelter Size Northeast Southeast Southwest West Limited Admission Open Admission

30 Shelter Size OR: 0.99 (0.98, 1) The larger the facility (greater number of dogs), the less likely that the facility will return a dog to owner.

31 Probability Probability for a Dog to be RTO Funding Source Mixed: OR: 2.22 (1.65, 2.99) Municipal: OF: 3.40 (2.67, 4.34) Private: Referent Mixed Municipal Private Funding Source

32 Probability for a Dog to be RTO Probability Midwest: OR: 0.59 (0.47, 0.74) Northeast: OR: 0.38 (0.22, 0.64) Southeast: OR: 0.24 (0.18, 0.32) Southwest: OR: 0.40 (0.29, 0.53) Region MW NE SE SW W Region

33 Probability for a Dog to be RTO Probability No Admission Type Limited admission: OR: 0.18 (0.07, 0.46) Open Admission: Referent Stray Admittance Yes

34 Euthanized

35 Number of dogs euthanized 70.0% 60.0% 50.0% Mean: Median: 7 Max: 2622 Min: 0 Relative Frequency 40.0% 30.0% 20.0% 10.0% 0.0% Number

36 Animals Euthanized in Shelters Variable Estimate Standard Error 95% Confidence Limits Intercept Funding Source P-value Mixed <.0001 Municipal Private Region Midwest <.0001 Admission Type Northeast Southeast Southwest West Limited Admission Open Admission Shelter Sixe <.0001

37 Shelter Size OR: (1.0003, ) The larger the shelter intake, the more likely they are to euthanize.

38 Probability for a Shelter to Euthanize a Dog Probability Funding Source Mixed: OR: 1.42 (0.58, 3.348) Municipal: OR:2.13 (0.90, 5.07) Private: OR: 1 (1,1) Mixed Municipal Private Funding Source

39 Probability Probability for a Shelter to Euthanize a Dog Region Midwest: OR: 1.62 (1.03, 2.59) Northeast: OR: 1.39 (0.46, 4.19) Southeast: OR: 5.1 (3.32, 7.87) Southwest: OR: 3.09 (1.77, 5.40) West: Referent 0 MW NE SE SW W

40 Probability for a Shelter to Euthanize a Dog Probability No Admission Type Limited Admission: OR: 0.14 (0.08, 0.59) Open Admission: referent Stray Admittance Yes

41 Client Frame Other Frames Repeats Simple Unbiased State M C R total shelters Florida South Carolina Maine Michigan Mississippi All R/C= 218/539= 0.40 (95% CI = )

42 Number of Dog Shelters 7,076 (95% CI = 6,399-7,890)

43 Number of Dogs Entering shelters: 5,532,904 (95% CI: 5,003,528-6,169,579) Adopted: 2,628,112 (95% CI: 2,376,660-2,930,531) Returned to Owner: 969,443 (95% CI: 876,689-1,080,998) Transferred: 778,385 (95% CI: 703, ,955) Euthanized: 776,970 (95% CI: 702, ,377)

44 Number of Dogs Total Number Lower 95% CI Upper 95% CI Shelters 7,076 6,399 7,890 Total Dogs 5,532,904 5,003,528 6,169,579 Adopted 2,628,112 2,376,660 2,930,531 Returned to Owner 969, ,689 1,080,998 Transferred 778, , ,955 Euthanized 776, , ,366

45 Number of Dogs 778, ,443 18% 14% 379,994 7% 776,970 14% 2,628,110 47% Adopted Euthanized Returned Transferred Other

46 Number of Dogs Mississippi State ASPCA HSUS Total shelters 7,076 13,600 3,500 Total Dogs 5,532, million NA Adopted 2,628, million NA Returned to Owner 969, ,000 NA Transferred 778,385 NA NA Euthanized 776, million NA

47 Conclusion There are several variables that affect the numbers and fates of dogs entering shelters across the United States Region Funding source Admission Type Number of intakes

48 Conclusion Why do we care? Understand pet population dynamics Transport program Management practices/policies System dynamics Identifying trends in dog numbers in animal shelters

Kern County Animal Services. Director s Monthly Report March 2018

Kern County Animal Services. Director s Monthly Report March 2018 Kern County Animal Services Director s Monthly Report March 2018 2 Program Highlights Rescue Rescue partners helped place 202 animals in March Foster KCAS Foster program continues to grow, and in the month