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Birth and Death Rate Estimates
of Cats and Dogs in U.S. Households
and Related Factors
John C. New, Jr. and William J. Kelch
Department of Comparative Medicine
University of Tennessee, Knoxville
Jennifer M. Hutchison
Australian Government Department of Agriculture, Fisheries, and
Forestry
Barton, Australia
Mo D. Salman and Mike King
Department of Clinical Sciences
Colorado State University
Janet M. Scarlett
Department of Population Medicine and Diagnostic Sciences
Cornell University
Philip H. Kass
Department of Population Health and Reproduction
University of California, Davis
Studies report variable factors associated with dog and cat surpluses in the United
States. Estimates of cat and dog birth and death rates help understand the problem.
This study collected data through a commercial survey company, distributing ques
-
tionnaires to 7,399 cat- and dog-owning households (HHs) in 1996. The study used an
JOURNAL OF APPLIED ANIMAL WELFARE SCIENCE, 7(4), 229–241
Copyright © 2004, Lawrence Erlbaum Associates, Inc.
Requests for reprints and/or copies of the questionnaires used in this study should be sent to John
New, Department of Comparative Medicine, 2407 River Drive, A205, Knoxville, TN 37996–4543.
Email: jnew@utk.edu
unequal probability sampling plan and reported estimates of means and variances as
weighted averages. The study used estimates of HHs and companion animals for na
-
tional projections. More than 9 million owned cats and dogs died during 1996—yield
-
ing crude death rates of 8.3 cat deaths/100 cats in HHs and 7.9 dog deaths/100 dogs in
HHs. The study reported twice as many kitten as puppy litters, with an average litter
size of 5.73 and 7.57, respectively. The study reported data on planned versus un
-
planned litters, reasons caregivers did not spay females, disposition of litters, and
sources of animals added to HHs. These first national estimates indicate the magni
-
tude of, and reasons for, animals leaving HHs. The crude birth rate was estimated to be
11.2 kittens/100 cats in HHs and 11.4 puppies/100 dogs in HHs.
The National Council on Pet Population Study and Policy (Council) was formed
in 1993 to gather and analyze data to characterize the number, origin, and dispo
-
sition of cats and dogs in households (HHs) in the United States. Several studies
were conducted in conjunction with the Council to explore factors associated
with the dog and cat surplus (Kass, New, Scarlett, & Salman, 2001; New et al.,
1999, 2000; Salman et al., 1998, 2000; Scarlett, Salman, New, & Kass, 1999).
These studies were based largely on data collected from 12 animal shelters in
four states with the purpose of identifying animal and human factors associated
with relinquishment of dogs and cats. However, HHs that relinquish cats and
dogs represent only one segment of the companion animal-owning population.
To understand better the factors that are associated with relinquishment
throughout the United States, it also is helpful to estimate baseline data on the na-
tional cat and dog population. Important baseline data on cats and dogs in U.S.
HHs include frequency and source of acquisition, frequency and method of dispo-
sition, reproductive status, reproductive history, and disposition of offspring. For
comparison purposes, scientists associated with the Council partnered with the
American Veterinary Medical Association (AVMA) during their general survey
of companion animal owning HHs (AVMA, 1997).
The Council’s Pet-Owning Household Survey was designed to collect data
from HHs with companion animals that had not been collected previously on a na
-
tional basis. Data collection included information on how animals left HHs and
how they were added to HHs, including births of litters and whether these were
planned or unplanned litters. Information was also collected on reasons why com
-
panion animal caregivers had not had females spayed prior to birth of unplanned
litters. The purpose of this article is to report the findings from this survey, includ
-
ing estimates of crude birth and death rates for cats and dogs.
MATERIALS AND METHOD
The Household Survey was conducted in 1997 and collected data on HHs in
1996. The survey was divided into two phases. Phase 1 was conducted by Na
-
230
NEW ET AL.
tional Family Opinion of Toledo, Ohio (NFO) in conjunction with the AVMA.
NFO maintains a panel of HHs that is representative of the United States and
that is based on size of HH, age of occupants, HH income, geographic location,
and other characteristics. The AVMA/NFO survey included 80,000 HHs. The
response rate was 75% and summary results were reported previously (AVMA,
1997). Based on responses to the Phase 1 survey, 12,960 HHs were identified as
having at least one cat and 14,947 as having at least one dog during 1996.
Phase 2 was a follow-up survey using a questionnaire (available from the first
author by request) designed by Council board members and their scientific advi
-
sory committee. Phase 2 included 7,399 HHs identified from Phase 1 as having
owned at least one dog and/or cat in 1996. The response rate was 89%, and HHs
surveyed were divided about equally between HHs with dogs and HHs with cats.
A small portion of HHs had both species and were asked to complete both the
cat-caregiver and dog-caregiver questionnaire (n = 601).
An unequal probability sampling plan was used to select the 7,399 HHs needed
for Phase 2. The size of the Phase 2 sample was determined by the study budget in
regard to the number of HHs that could be surveyed a second time. All HHs indi-
cating that a dog and/or cat left the HH during the year were included (n = 3,087).
The remainder of the sample was randomly selected (n = 4,312). The
Horvitz–Thompson Estimator (Thompson, 1992) was used to get an unbiased esti-
mate of proportions (percentages) and variances.
Percentages reported in this article are weighted averages that reflect the sam-
pling plan and assume that nonresponders do not differ significantly from respond-
ers. To get estimates of total numbers of HHs and animals, the unbiased estimates
were multiplied by the number of HHs or animals reported during Phase 1—31.2
million dog-owning HHs and 27.0 million cat-owning HHs (AVMA, 1997).
The additional variance resulting from multiplying the two estimates (percent
-
ages and number of HHs or animals) was assumed to be insignificantly small re
-
garding data in all tables. HHs that reported having at least one litter of kittens or
puppies were cross-classified based on whether the litters were planned and the
number of litters reported. Cross-classification by number of animals in the HH
(single- or multiple-animal HHs) and whether a litter was born (yes or no) was also
performed. Associations of these cross-classifications were evaluated by
chi-square analysis. Odds ratios (ORs) and 95% confidence intervals (CIs) were
calculated for the data on litters as effect measures from stratified analysis (Man
-
tel–Haenszel) using Epi-Info (Dean et al., 1994); p values less than .05 were con
-
sidered statistically significant.
RESULTS
The 6,573 HHs that returned questionnaires comprised the basis of the following
tables. Approximately equal numbers of HHs with cats (n = 3,558) and HHs
CAT AND DOG BIRTH AND DEATH RATES 231
with dogs (n = 3,530) returned questionnaires. Of HHs that responded, 515 had
both species. Table 1 presents the estimated number of cats and dogs who left
HHs during 1996 and the reasons they left. The most frequent reason reported
was that the cat or dog died or was killed. Specific causes of death were not col
-
lected. Because euthanasia was a different category, these deaths are assumed to
be natural, accidental, or intentional (other than euthanasia) deaths.
Caregivers reported that 3.4 million cats and 2.4 million dogs died during the
year. Additional cats and dogs were euthanized because of illness, age, or other
reasons. Rarely did respondents indicate what the other reasons were for having an
animal euthanized. One reason given was that euthanasia was recommended by
health authorities because of exposure to a known, or potentially, rabid animal.
The Phase 2 survey estimated that more than 9 million dogs and cats died (all rea
-
sons) during the year. The Phase 1 survey estimated that there were 59.1 million
cats and 52.9 million dogs in HHs during 1996 (AVMA, 1997). Using these esti
-
mates, the crude death rate for cats and dogs in 1996 was 8.3 cat deaths per 100 cats
in HHs and 7.9 dog deaths per 100 dogs in HHs.
The “disappeared” category included animals reported stolen and those who
“ran off/wandered off.” Three times more cats than dogs disappeared. The survey
estimates that almost a million more cats than dogs were given away. Fewer dogs
than cats were relinquished to shelters or taken away by animal control officers.
Not enough cats were sold to evaluate further this reason for leaving.
Table 2 presents data on the percentage and numbers of litters and animals from
the litters born during the study year. A total of 317 (9.2%) of 3,457 cat-owning
HHs that answered the question about litters reported litters born during the study
year. A total of 3,158 kittens (727 male, 815 female, and 1,616 of unknown sex)
were reported from 598 litters. A total of 216 (216/317, 68%) reported that the lit
-
ters of kittens were unplanned; of these, 101 HHs (101/216, 47%) reported more
than one litter during the study year (M = 2.9 litters per HH with multiple un
-
planned litters). Sixty-eight HHs (68/317, 21%) reported that the litters were
planned; of these 34 HHs (34/68, 50%) reported more than one litter during the
study year (M = 2.9 litters per HH with multiple-planned litters). Planning infor
-
mation was not provided for 33 HHs that reported litters. The association between
planning and number of litters was not statistically significant with HHs that
planned litters being no different from HHs in which litters were not planned re
-
garding multiple litters (OR = 1.06; 95% CI = 0.59, 1.91; p = .82). The odds of
multiple-cat HHs reporting at least one litter were 8.35 times higher than were sin
-
gle-cat HHs (95% CI = 5.55, 12.65; p < .001).
One hundred fifty-four (4.4%) of 3,423 dog-owning HHs that answered the ques
-
tion about litters reported litters of puppies born during the study year. A total of
1,349 puppies (676 male, 650 female, and 23 of unknown sex) were reported from
255 litters. Eighty-seven HHs (87/154, 56%) reported that the litters were un
-
planned; of these, 18 (18/87, 21%) reported more than onelitterduringthestudyyear
232
NEW ET AL.
TABLE 1
Estimates of Cats and Dogs That Left U.S. HHs in 1996 and Why They Left
% of HHs That Had at
Least 1 Cat Leave No. of HHs No. of Cats
% of HHs That Had at
Least 1 Dog Leave No. of HHs No. of Dogs
N SD 95% CI N 95% CI N 95% CI N SD 95% CI N 95% CI N 95% CI
HHs that had at least 1
animal leave
because it: 23.1 0.7 21.8, 24.4 6.24 5.89, 6.59 11.27 10.64, 11.90 20.8 0.7 19.5, 22.1 6.49 6.08, 7.00 7.13 6.68, 7.69
Died or was killed 8.3 0.4 7.6, 9.0 2.23 2.04, 2.42 3.43 3.14, 3.72 6.8 0.3 6.2, 7.5 2.15 1.94, 2.36 2.44 2.20, 2.68
Was
euthanized—Ill/old 4.5 0.3 4.0, 5.0 1.22 1.07, 1.36 1.34 1.18, 1.50 5.1 0.3 4.6, 5.7 1.60 1.43, 1.77 1.60 1.43, 1.77
Was
euthanized—Other 0.4 0.1 0.24, 0.54 0.11 0.07, 0.15 0.13 0.08, 0.18 0.7 0.1 0.5, 0.9 0.21 0.15, 0.28 0.21 0.15, 0.28
Died (all reasons) 13.2 0.5 12.3, 14.1 3.56 3.31, 3.80 4.90 4.56, 5.23 12.7 0.5 11.8, 13.6 3.96 3.68, 4.23 4.16 3.87, 4.45
Disappeared 4.9 0.3 4.3, 5.5 1.33 1.17, 1.49 1.90 1.68, 2.13 1.9 0.2 1.5, 2.3 0.60 0.48, 0.73 0.60 0.48, 0.73
Was given away 4.1 0.3 3.6, 4.7 1.12 0.97, 1.27 2.86 2.47, 3.25 3.6 0.3 3.1 , 4.1 1.13 0.96, 1.29 1.96 1.67, 2.25
Went to shelter/animal
control 1.2 0.2 0.9, 1.5 0.32 0.24, 0.41 0.64 0.48, 0.81 0.8 0.1 0.7, 1.0 0.25 0.21, 0.30 0.45 0.37, 0.53
Was sold Insufficient data NA NA 0.8 0.1 0.5, 1.0 0.24 0.16, 0.32 1.18 0.78, 1.58
Left for other reasons 0.6 0.1 0.4, 0.9 0.17 0.11, 0.24 0.28 0.17, 0.38 0.5 0.1 0.3, 0.7 0.15 0.09, 0.22 0.20 0.11, 0.28
Note. Numbers of HHs and animals are in millions. HHs could have lost more than one animal during the year for different reasons. HHs = households; NA = not applicable.
(M = 3.6 litters per HHs with multiple-unplanned litters). Sixty HHs (60/154, 39%)
reported that the litters were planned; of these, 20 HHs (20/60, 33%) reported more
than one litter during the study year (M = 3.8 litters per HHs with multiple-planned
litters). The association between planning and number of litters was statistically sig
-
nificant, with the odds of multiple litters occurring in HHs that planned litters being
2.68 times greater than HHs in which litters were not planned (95% CI = 1.10, 6.61; p
< .02). The odds of multiple-dog HHs reporting litters were 9.47 times greater than
were single-dog HHs (95% CI = 5.71, 15.88; p < .001).
Almost twice as many HHs reported having at least one litter of kittens than re
-
ported at least one litter of puppies, and more than twice as many litters of kittens
234
NEW ET AL.
TABLE 2
Estimated Percentage and Number of Litters (Planned and Unplanned) of Kittens
and Puppies Born in U.S. HHs in 1996
Kittens Puppies
N SD 95% CI N SD 95% CI
% of all U.S. cat- or dog- owning HHs
that had at least 1 litter born 5.2 0.3 4.5, 5.9 2.6 0.3 2.1, 3.1
% of HHs that had at least 1
planned litter 1.1 0.2 0.7 , 1.4 1.2 0.2 0.8, 1.6
% of HHs that had at least 1
unplanned litter 3.6 0.3 2.9, 4.2 1.4 0.2 1.0, 1.7
No. of HHs that had at least 1 litter
a
1.40 1.22, 1.58 0.81 0.64, 0.98
No. of HHs that had at least 1
planned litter 0.34 0.23, 0.44 0.37 0.25, 0.49
No. of HHs that had at least 1
unplanned litter 1.11 0.92, 1.31 0.42 0.31, 0.54
No. of litters born in U.S. HHs
a
2.59 2.26, 2.92 1.16 0.92, 1.40
No. of litters that were planned 0.66 0.45, 0.86 0.60 0.40, 0.80
No. of litters that were unplanned 2.10 1.73, 2.47 0.55 0.40, 0.70
No. of animals born in U.S. HHs
a
6.63 5.78, 7.48 6.04 4.78, 7.30
No. of animals from planned litters
a
1.75 1.20, 2.30 3.38 2.27, 4.49
No. of animals from unplanned
litters 5.46 4.50, 6.43 2.60 1.88, 3.32
M
b
no. of litters born in HHs that had
at least 1 litter 1.72 1.45
M
b
no. of animals born in U.S. HHs
that had at least 1 litter 5.73 7.57
Note. HHs = households.
a
Given in millions.
b
Not all HHs that reported having at least one litter provided the number of litters
and the number of animals born. These means are based on 267 of 317 cat-owning HHs and 149 of 154
dog-owning HHs that reported at least one litter being born in 1996 and provided the number of litters
and animals born.
were reported than litters of puppies (Table 2). However, a similar number of kit
-
tens and puppies were born because the mean number of animals born per litter
was less for kittens (M = 5.73) than for puppies (M = 7.57). The estimated number
of HHs that had at least one planned litter of kittens (0.34 million) or puppies (0.37
million) was similar, as was the number of HHs that reported at least one un
-
planned litter of puppies (0.42 million). However, there were more than three
times as many HHs with unplanned litters of kittens (1.11 million). The estimated
number of litters was similar for the categories of planned litters of kittens (0.66
million), puppies (0.60 million), and unplanned litters of puppies (0.55 million).
There were more than three times as many unplanned litters of kittens (2.1 mil
-
lion) compared to the other categories. More puppies came from planned litters
than unplanned litters (3.38 million and 2.60 million, respectively). However,
there were more than three times as many kittens from unplanned litters versus
planned litters (5.46 million and 1.75 million, respectively). The mean number of
litters of kittens and puppies per HH that reported at least one litter was similar (M
= 1.72 and 1.45, respectively). On average, however, the number of puppies born
per litter (7.57 average number of puppies per litter/1.45 average litters born = 5.2)
was larger than that for kittens (5.73/1.72 = 3.3). Using the Phase 1 survey esti-
mates of total number of animals in HHs during 1996 (AVMA, 1997), the crude
birth rate was 11.2 kittens born per 100 cats in HHs and 11.4 puppies born per 100
dogs in HHs.
Of those HHs that reported having at least one unplanned litter of puppies or
kittens during the year, we asked the reason(s) for not having the mother of the lit-
ter spayed before pregnancy (Table 3). Respondents could give multiple reasons.
Cost was the most frequent reason given by HHs with litters of kittens, whereas
“Did not know she was in heat” was the most frequent reason given by HHs with
litters of puppies. In general, HHs with litters of kittens gave more varied reasons
for not having the mother spayed before pregnancy than did HHs with litters of
puppies. Some respondents indicated they thought that the procedure (spaying)
was dangerous, but there were insufficient data for either species on which to base
national estimates.
Other reasons given for not having the procedure done prior to the birth of kit
-
tens included the following:
1. Some cats were strays and showed up at the HHs already pregnant.
2. Others were considered wild, feral, or “barn cats.”
3. Some respondents indicated they wanted kittens. For HHs that had litters of
puppies, specific other reasons given for not having the procedure done
were rarely provided and showed no apparent pattern.
Table 4 displays the disposition of kittens and puppies from sampled HHs. Kit
-
tens most frequently were given away, reported to have died, were killed, or were
CAT AND DOG BIRTH AND DEATH RATES 235
TABLE 3
Estimates of U.S. Cat- and Dog-Owning HHs in 1996 That Had Unplanned Litters by Reason for Not Having the Mother Spayed
% of All Cat-Owning HHs
No. of Cat-Owning
HHs % of All Dog-Owning HHs
No. of Dog-Owning
HHs
Reasons
a
N SD 95% CI N 95% CI N SD 95% CI N 95% CI
Could not afford 1.8 0.2 1.4, 2.2 0.49 0.38, 0.60 0.6 0.1 0.4, 0.9 0.17 0.11, 0.23
Going to get rid of 0.05 0.01 0.03, 0.06 0.013 0.008, 0.017 Insufficient data
Did not know she was in heat 0.6 0.1 0.4, 0.8 0.15 0.10, 0.21 1.8 0.2 1.4, 2.2 0.49 0.38, 0.60
Do not believe in altering animals 0.4 0.1 0.2, 0.6 0.10 0.05, 0.16 Insufficient data
Procedure is inconvenient 0.8 0.1 0.5, 1.0 0.2 0.14, 0.27 Insufficient data
Forgot/no time 0.06 0.01 0.04, 0.08 0.49 0.38, 0.60 0.25 0.07 0.1, 0.39 0.07 0.03, 0.10
Thought she was too young 0.4 0.1 0.2, 0.6 0.11 0.07, 0.16 0.13 0.01 0.11, 0.15 0.035 0.029, 0.042
Other reasons 0.9 0.1 0.6, 1.2 0.25 0.17, 0.32 0.36 0.1 0.17, 0.55 0.10 0.05, 0.15
Note. Numbers of HHs and animals are in millions. HHs = households.
a
Of all HHs reporting that they had at least one unplanned litter, these are the reasons given for not having had the mother spayed before pregnancy. HHs could
have given more than one reason for not having the mother of an unplanned litter spayed.
236
still in the HHs. Puppies most frequently were reported as sold or given away.
Compared to puppies, approximately 1 million more kittens were given away,
died, were killed, or were still in the home. More than 2 million more puppies than
kittens were sold (relatively few kittens were sold), but more kittens than puppies
disappeared. Similar numbers of kittens and puppies were taken to animal shelters.
Only a few caregivers of litters of puppies indicated an “other” disposition such as
giving puppies to the caregiver of the sire of the litter (“pick of the litter”). The
most frequent other disposition of kittens had to do with the mother and kittens be-
ing wild, feral, or barn cats. Although this is not a disposition, not enough informa-
tion was given, or known, to classify these kittens in any other category.
Table 5 shows the number of cats and dogs added to HHs during the year by
source. An estimated total of 4.62 million HHs (17.1%) added an estimated total of
8.6 million cats. More than one source was possible per HH that reported adding a
cat. Cats were added to HHs most often—based on the percentage of HHs—be
-
cause they were abandoned or stray (“just showed up”), representing 30.9% of
HHs that added cats and 24.1% of all cats added. Friends or neighbors were a
source of cats for 15.5% of HHs that added cats and 12.9% of cats added to HHs.
Offspring of cats already in the HH were the source of new cats for 15.2% of HHs
and 34.4% of cats added. Shelters were the source of new cats for 13.2% of HHs
and 9.5% of all cats added. Strangers were the source of cats for 7.7% of HHs and
6.4% of cats.
New dogs most often came from breeders—with 18.8% of HHs that added a
dog reporting this source and 15.8% of new dogs coming from this source. Friends
or neighbors were the source of new dogs for 16.7% of HHs and 14.3% of dogs
added. Strangers were the source of new dogs for 13.4% of HHs and 10.7% of dogs
CAT AND DOG BIRTH AND DEATH RATES 237
TABLE 4
Estimated Number in Millions of Kittens and Puppies Born in U.S. Households in 1996,
by Disposition
Kittens Puppies
Disposition N 95% CI N 95% CI
Given away 2.91 2.50, 3.32 1.93 1.52, 2.34
Taken to shelter 0.32 0.28, 0.37 0.41 0.32, 0.49
Sold/given to pet shop 0.06 0.05, 0.07 0.14 0.11, 0.17
Sold to an individual 0.11 0.10, 0.13 2.19 1.73, 2.66
Kept/still have 1.51 1.30, 1.72 0.52 0.41, 0.63
Euthanized 0.15 0.13, 0.18 Insufficient data
Died/killed 1.67 1.44, 1.91 0.40 0.31, 0.48
Disappeared 0.12 0.10, 0.14 0.033 0.026, 0.04
Other 0.11 0.09, 0.12 Insufficient data
TABLE 5
Estimates of Source of Cats and Dogs Added to U.S. HHs in 1996
% of HHs That Had at
Least 1 Cat Added No. of HHs No. of Cats
% of HHs That Had at
Least 1 Dog Added No. of HHs No. of Dogs
N SD 95% CI N 95% CI N 95% CI N SD 95% CI N 95% CI N 95% CI
HHs that had at
least 1 animal
added from: 17.1 0.7 15.8, 18.5 4.62 4.25, 4.99 8.60 7.92, 9.28 13.6 0.7 12.3, 14.9 4.25 3.84, 4.66 5.99 5.41, 6.57
Offspring 2.9 0.2 2.4, 3.4 0.79 0.66, 0.92 2.96 2.47, 3.45 1.6 0.2 1.1, 2.0 0.50 0.36, 0.64 1.59 1.14, 2.03
Pet shop 0.6 0.1 0.3, 0.9 0.16 0.09, 0.23 0.19 0.10, 0.27 0.5 0.1 0.2, 0.7 0.14 0.06, 0.22 0.17 0.07, 0.26
Breeder 0.2 0.05 0.1, 0.3 0.06 0.03, 0.08 0.08 0.04, 0.11 2.7 0.3 2.1, 3.3 0.84 0.66, 1.02 0.95 0.75, 1.16
Shelter 2.5 0.3 2.0, 3.1 0.69 0.54, 0.83 0.82 0.65, 0.99 1.5 0.2 1.1, 2.0 0.48 0.34, 0.62 0.51 0.36, 0.66
Veterinarian 0.3 0.1 0.1, 0.5 0.09 0.04, 0.14 0.09 0.04, 0.15 0.15 0.07 0.01, 0.28 0.05 0.003, 0.09 0.05 0.003, 0.1
Rescue group 0.2 0.09 0.05, 0.39 0.06 0.01, 0.10 0.09 0.02, 0.15 0.3 0.1 0.08, 0.47 0.08 0.02, 0.15 0.11 0.03, 0.18
Friend/neighbor 3.0 0.3 2.4, 3.6 0.81 0.65, 0.96 1.11 0.90, 1.32 2.4 0.3 1.9, 3.0 0.75 0.58, 0.93 0.86 0.66, 1.05
Family 0.9 0.1 0.6, 1.2 0.25 0.17, 0.32 0.29 0.20, 0.38 0.7 0.1 0.4, 0.9 0.21 0.13, 0.29 0.26 0.16, 0.36
Stranger 1.5 0.2 1.1, 1.8 0.40 0.30, 0.50 0.55 0.41, 0.69 1.9 0.2 1.4, 2.4 0.60 0.45, 0.74 0.64 0.48, 0.80
Abandoned/stray 6.0 0.4 5.1, 6.8 1.61 1.39, 1.83 2.07 1.78, 2.35 1.7 0.2 1.2, 2.2 0.53 0.38, 0.67 0.54 0.39, 0.69
Gift 0.9 0.2 0.6, 1.2 0.25 0.16, 0.34 0.27 0.17, 0.36 0.6 0.1 0.3, 0.9 0.20 0.11, 0.29 0.22 0.12, 0.31
Other sources 0.2 0.1 0.03, 0.3 0.04 0.01, 0.07 0.08 0.02, 0.13 0.3 0.1 0.1, 0.5 0.10 0.03, 0.17 0.10 0.03, 0.17
Note. Numbers of HHs and animals are in millions. HHs could have added more than one animal during the year for different reasons. HHs = households.
added, and dogs that were abandoned or stray were the source for 11.8% of HHs
and 9.0% of new dogs. Offspring of dogs already in the HH was the source of new
dogs for 11.2% of HHs and 26.5% of new dogs, and 10.7% of HHs reported that
they added a dog from a shelter, which represents 8.5% of new dogs.
Dogs and cats born in the HH were the most frequently reported source of new
animals (34.4% of cats and 26.5% of dogs added). Compared to dogs, more than a
million more cats were added to HHs by being born there or by being adopted as
abandoned or stray cats. Compared to cats, almost a million more dogs came from
breeders.
DISCUSSION AND CONCLUSIONS
To our knowledge, these are the first national estimates of the magnitude of, and
reasons for, animals leaving HHs. These data are also the first estimates of birth
-
rates on a national basis. Approximately 1 million more cats than dogs died—or
were killed—during this period. The crude death rate, based on all known deaths
from all causes, was similar for cats and dogs at approximately 8% during 1996.
Because, however, some of the animals that disappeared probably died or were
killed, the crude death rate must be considered a minimum estimate. Because of
the disproportionate number of cats who disappeared, the crude death rate for
cats. in particular, must be considered an underestimate.
A large number of animals are dying each year by means other than euthanasia.
This is true especially of kittens. This raises questions as to the causes and methods
of these deaths, but such data were not collected in this survey. That more cats than
dogs died, were killed, or disappeared may suggest less attention or concern by cat
caregivers, in general, compared to dog caregivers. Caregiver expectations of cats
(the assumption that it is a cat’s nature to disappear for a few days and then return)
also may explain some of this disparity. It would be valuable to know what efforts
were made to find dogs and cats who disappeared and determine if these efforts
differed by species, but these data were not collected. These findings, along with
the estimate that almost a million more cats than dogs were given away, suggest
that different values are being placed on these two species.
These data also suggest the fluid nature of the cat population, with many cats
disappearing from some HHs and at least some being added to other HHs as aban
-
doned or stray animals. This phenomenon has been suggested by others (Patronek,
Beck, & Glickman, 1997) and complicates attempts to measure accurately the dy
-
namics of this particular population. Whether this phenomenon reflects the basic
nature of cats, perceptions or attitudes of caregivers, or a combination of the two
plus other factors is an area that needs more study.
Although a similar number of kittens and puppies were born during 1996, im
-
portant differences exist. The number of unplanned litters of kittens is disturbing
CAT AND DOG BIRTH AND DEATH RATES 239
and justifies increased efforts aimed at promoting surgical neutering. That a large
percentage of kittens born in HHs were of unknown sex (caregiver did not know
the sex) may contribute to the cat surplus. Caregivers who intend to keep some of
the kittens but also intend that the ones they keep are of the same sex may end up
with additional unplanned litters. When combined with information on the dispo
-
sition of kittens compared with puppies, the picture is bleaker. More kittens than
puppies died or were given away, and, compared to puppies, fewer were sold. Fur
-
thermore, it must be remembered that these data are based on responses by people
who admit to some relationship with the cats. We did not collect any data on the fe
-
ral cat population and its dynamics in the United States.
The relative value of cats compared to dogs, as perceived by caregivers and so
-
ciety in general, has been a subject of some discussion. As early as 1904, Hall and
Browne published data showing that dogs were considered much more manly than
cats. Others have also identified differences between cat and dog caregivers (Kidd
& Kidd, 1980; Perrine & Osbourne, 1998). These findings point to a need to con
-
sider strongly the human characteristics (knowledge, attitudes, expectations, expe-
rience) of cat and dog caregivers to understand better the dynamics that make some
animals valued members of a HH and others only marginal and disposable mem-
bers. Because these data were collected in 1997 on HHs with cats and dogs in
1996, they may not represent current situations in HHs. To estimate trends, repli-
cation of this study in some form would be necessary.
ACKNOWLEDGMENTS
This study was conducted under the auspices of the National Council on Pet
Population Study and Policy. Funding was provided by American Animal Hos
-
pital Association, American Veterinary Medical Association, Humane Society
of the United States, Massachusetts Society for the Prevention of Cruelty to Ani
-
mals, PetsMart Charities, Colorado State University, and the University of Ten
-
nessee. We thank J. Karl Wise, Brad Gehrke, and Claire Louise Adams of the
American Veterinary Medical Association Center for Information Management,
and Arnold Saxton of the University of Tennessee Institute of Agriculture for
their invaluable assistance with this project.
REFERENCES
American Veterinary Medical Association. (1997). U.S. pet ownership & demographics sourcebook.
Schaumburg, IL: Author.
240 NEW ET AL.
Dean, A. G., Dean, J. A., Coulombier, D., Brendel, K. A., Smith, D.C., Burton, A. H., et al. (1994). Epi
Info (Version 6) [Word processing, database, and statistics program for epidemiology on microcom
-
puters]. Atlanta, GA: Centers for Disease Control and Prevention.
Hall, G. S., & Browne, C. E. (1904). The cat and the child. Pedagogical Seminary, 11, 3–29.
Kass, P. H., New, J. C., Jr., Scarlett, J. M., & Salman, M. D. (2001). Understanding animal companion
surplus in the United States: Relinquishment of nonadoptables to animal shelters for euthanasia.
Journal of Applied Animal Welfare Science, 4, 237–248.
Kidd, A. H., & Kidd, R. M. (1980). Personality characteristics and preferences in pet ownership. Psy
-
chological Reports, 46, 939–949.
New, J. C., Jr., Salman, M. D., Scarlett, J. M., Kass, P. H., King, M., & Hutchison, J. M. (2000). Shelter
relinquishment: Characteristics of shelter-relinquished animals and their owners compared with an
-
imals and their owners in U.S. pet-owning households. Journal of Applied Animal Welfare Science,
3, 179–201.
New, J. C., Jr., Salman, M. D., Scarlett, J. M., Kass, P. H., Vaughn, J. A., Scherr, S., et al. (1999).
Moving: Characteristics of dogs and cats and those relinquishing them to 10 U.S. animal shelters.
Journal of Applied Animal Welfare Science, 2, 83–96.
Patronek, G. J., Beck, A. M., & Glickman, L. T. (1997). Dynamics of dog and cat populations in a com
-
munity. Journal of the American Veterinary Medical Association, 210, 637–642.
Perrine, R. M., & Osbourne, H. L. (1998). Personality characteristics of dog and cat persons.
Anthrozoös, 11(1), 33–40.
Salman, M. D., Hutchison, J. M., Ruch-Gallie, R., Kogan, L., New, J. C., Jr., Kass, P. H., et al. (2000).
Behavioral reasons for relinquishment of dogs and cats to 12 shelters, Journal of Applied Animal
Welfare Science, 3, 93–106.
Salman, M. D., New, J. C., Scarlett, J., Kass, P., Ruch-Gallie, R., & Hetts, S. (1998). Human and animal
factors related to the relinquishment of dogs and cats in 12 selected animal shelters in the U.S.A.
Journal of Applied Animal Welfare Science, 1, 207–226.
Scarlett, J. M., Salman, M. D., New, J. C., & Kass, P. H. (1999). Reasons for relinquishment of compan-
ion animals in U.S. animal shelters: Selected health and personal issues. Journal of Applied Animal
Welfare Science, 2, 41–57.
Thompson, S. K. (1992). Sampling. New York: Wiley.
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