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Question Examine for what reason and to what affects it is crucial for all companion
animals be spayed and neutered
Subject Environmental Systems & Societies
Topic Companion Animal Health
Candidate Name Nicole Seitz
Candidate Number 007005-0153
Session May 2014
School Downingtown STEM Academy
Supervisor: D. Timm-Dinkins
Word Count: 3623
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Abstract
In this investigation I am looking to find the how spaying and neutering
companion animals affects the individual health as well as the population’s overall health
and well being. Spaying and neutering animals is a very controversial topic between
groups such as breeders and others like shelters. This investigation aims at finding how
spaying and neutering these companion animals is crucial with evidence and facts
gathered from a plethora of various scholarly, primary, and secondary sources. The
question of this investigation is: Examine for reason and to what affects it is crucial for
all companion animals be spayed and neutered.
In order to find sources explaining the importance of altering companion animals
I searched for a variety of sources. I found books, journals, articles, studies, and previous
research papers done on the subject. I read and examined each of all the sources and
pulled out any information about spaying and neutering companion animals, either on a
individual or overall population level. The sources I found had a plethora of information
that was both on a primary, and secondary level that provided much insight into the
question asked. Three or so of the sources exclusively presented the benefits to early
sterilization. One research paper that proves that sterilization will give the animal a
longer life span, and reproduction will cut back on the life span of the dog. Four sources
examine the affects of spaying and neutering on the population and well being of
companion animals. Two sources talk about how the public views sterilization, and its
consideration in responsible ownership of a companion animal. One last source examined
behavior problems associated with intact companion animals that linked them directly
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back to hormones present because the animal was still intact, where a sterilized animal
did not have the hormones present, and presented no behavior problems.
I concluded that it is in fact crucial to spay and neuter companion animals. The
research showed that euthanasia rates of animals in shelters would drop, the reason there
is euthanasia in shelters is because there is so much of a pet overpopulation. With
millions of pets homeless everyday creating more just adds to the problem, therefore to
benefit the population of companion animals, as a whole sterilization is the only solution
as it prevents reproduction to keep occurring when healthy animals are being put to death
daily. I also concluded on an individual basis that sterilization will increase the lifespan
of an animal, as well as prevent behavior problems. All in all the research proved that it is
in fact vital to spay and neuter companion for the health, behavior, and overpopulation to
the affects of longevity, positive behaviors, and the prevention of euthanasia of millions
of shelter animals daily.
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Table of Contents
Section: Page:
Abstract……………………………………………….……………….2
Table of Contents……………………………….………………..……4
Introduction……………………………………….………….………..5
Investigation………………………………….………………..……….7
Analysis/Evaluation..………………………….…………….…….…..15
Conclusion………………………………………….………….……….19
Bibliography………………………………………………..…….……20
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Introduction
This investigation covers the reasons and affects that make spaying and neutering
companion animals crucial for both the individual animal as well as companion animals
as a whole
This investigation is focused on examining the reasons and affects that make
sterilizing (spaying/neutering) companion animals crucial to the well being of the
individuals, and companion animals as a whole group. Companion animals in terms of
this investigation are referring to dogs, and cats. Sterilization or altering of an animal is a
quick process where in females (spaying) the uterus is removed, and in males (neutering)
the testicles are removed. This is a quick procedure done in about 5-10 minutes for males
animals, and 10-15 minutes for females.
The process is very quick, and the
recovery is as well. Any certified doctor
of veterinary medicine does this surgical
procedure. These are done at private
vets, out of clinics, and even out of
mobile sterilization vans. This procedure ensures that the animal is unable to reproduce
by removing the reproductive organs at the earliest of 4 months of age. Spaying and
neutering is most commonly done with cats and dogs, as they are the most common
companion animals. But also stretches to other companion animals such as rabbits.
These are the animals that when you walk through an animal shelter you will see the most
of. Ray (2008) says “An unplanned pregnancy puts both mother and kittens at risk of
being sent to a shelter.” (pg. 1). Therefore I come to the question of how crucial is it to
sterilize companion animals on an individual, and whole group level.
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The reason I choose this topic was because I am very involved with animal
rescue and see the affects of uneducated people who do not spay and neuter there animals
during my time working in the animal rescue. I see so many cats and dogs without homes
that could be so easily prevented with a 10-minute procedure. There are arguments that
breeders make that they have to keep breeding there specific breed to keep it going, but
the fact is the shelter dogs are purebreds, and until all the shelter animals stop having to
be put down because of overpopulation there is no reason in for anyone to breed a
companion animal. I am interested in becoming a doctor of veterinary science and to use
my expertise in the field of animal rescue. I also choose to write this paper because not
only should companion animals be spayed and neutered to benefit them as a whole group
but to also show how spaying and neutering them will affect them individually.
Companion animals are meant to be companions and not a tool to be used for breeding
and profit therefore why wouldn’t someone do something that is in the best interest of the
health of your companion. These reasons are why I personally choose this question to
examine.
The reason spaying and neutering a companion animal is so crucial will be
examined in this paper by a variety of scholarly, primary, and secondary sources that
have research performed or facts that will help the examination of the question. The aim
is through examining and analyzing the sources to prove how crucial the process of
sterilization is to benefit companion animals as a whole and a group by means of
lowering euthanasia rates, increasing life spans of individual animals, and preventing
behavior problems.
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Investigation
With a variety of sources I pulled out information that is reputable and explains the
importance of spaying and neutering companion animals. These sources come from
individual studies, independent research, scholarly journal articles, newspaper articles,
primary sources, and secondary sources. The information is listed below in bullet points
to present each point individually and to be later analyzed.
Abrams (2013) says “Spayed and neutered dogs lived an average of a year and a
half longer than dogs that retained their reproductive ability.” (pg. 1) based on a
study conducted by University of Georgia when they looked at over 40,000
records of deaths of pet dogs dating back to 1980.
o Abrams (2013) also showed from this conducted study “The increase in
life expectancy was 13.8 percent for male dogs, and 26.3 percent for
females.” (pg. 1)
o Abrams (2013) also writes as part of the research “The sterilized dogs
were more likely to die from cancer or autoimmune diseases; the intact
dogs died more often from infectious disease or trauma.” (pg. 1)
Abrams (2013) explains this phenomenon by “Sterilized dogs tend
to grow more, which may explain their increased likelihood of
developing cancer, and intact dogs are more aggressive and prone
to roaming, which may explain the infectious disease.” (pg. 1)
Lee (2009) explains pet overpopulation in New York kill shelters in her article
Spay and Neuter Program Fights Pet Abandonment by “The program is part of a
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successful effort to reduce New York City’s pet euthanasia rate, with a goal of
eventually achieving a “no-kill” policy for healthy pets in shelters” (pg. 1)
Frank (2004) explains in his book An Interactive Model of Human and
Companion Animal Dynamics: The Ecology and Economics of Dog
Overpopulation and the Human Costs of Addressing the Problem “Humans also
have a responsibility for addressing dog overpopulation since they are in a sense
the perpetuators of the problem. Pet store suppliers, commercial breeders, and
private owners (or "backyard breeders") intentionally produce millions of
animals every year to meet public demand. Millions of consumers initially decide
to purchase or adopt a dog, only to later abandon that animal because it is
inconvenient or no longer suits their needs. Millions more choose not to spay or
neuter their dog. Therefore, it is human actions and inaction that perpetuate dog
overpopulation and create the need for the human-made "solution" of
euthanasia.” (pg. 108)
o Frank (2004) explains how overpopulation is affecting society in an
economic way “ocusing specifically on dog overpopulation, there are
multiple costs to human society. According to Rowan (1992) shelters
spend approximately $1 billion every year to deal with unwanted
companion animals. Baetz (1992) estimates that $500 million is paid each
year for animal control by United States cities and counties. Other costs
include dog bites which result in 20 deaths and 585,000 injuries a year
(Gershman et al., 1994).” (pg. 108)
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o Frank (2004) shows the simple solution to the problem with “One very
promising method of addressing overpopulation is increasing spay/neuter
rates.” (pg. 109)
o Frank (2004) also explains, “He also points out that sterilization can
reduce behavioral problems which are a major cause of pet
abandonment.” (pg. 110)
New York Times author Klinkenborg (2007) writes “The rate at which dogs are
purchased and euthanized in this country is not a sign of our affection for them.
It’s a sign of our indifference.” (pg. 1)
Klinkenborg (2007) writes how catastrophic 1 new animal brought into any
situation with the comparison “another cat joins the enormous tribe of feral cats,
whose effect on the bird population is catastrophic, and another dog finds itself in
jail awaiting execution.” (pg. 1)
Hoffman (2013) the author of the research article Reproductive Capability Is
Associated with Lifespan and Cause of Death in Companion Dogs explains “We
found that sterilization was strongly associated with an increase in lifespan, and
while it decreased risk of death from some causes, such as infectious disease, it
actually increased risk of death from others, such as cancer.” (pg. 1)
o Hoffman (2013) than explains this with “the relationship between
sterilization and disease-specific risk of death is confounded with age. If
elective sterilization increases life expectancy, then sterilized dogs might
have a higher occurrence of diseases that occur late in life (such as
cancer) simply because sterilized dogs live longer.” (pg. 2)
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Hoffman (2013) says “elective surgical sterilization by ovariohysterectomy
("spay") or orchiectomy ("castration" or "neuter") is commonly performed at a
young age in pet dogs in North America for the management and behavioral
benefits it confers” (pg. 2)
Sterilized Dog Deaths proving Sterilization decreases a lot of potential
complications and furthers the animals lifespan
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Hoffman (2013) continues with “both the direction and magnitude of the effect of
sterilization on cause of death was markedly similar in males and females” (pg.
3)
Hoffman (2013) also shows all the benefits of sterilization like “sterilized dogs
had a decreased risk of death due to infection, and avoidance of infection may
partly explain their longer lifespans. The relationship between sterilization and
infectious disease could arise due to increased levels of progesterone and
testosterone in intact dogs, both of which can be immunosuppressive” (pg. 5)
o Hoffman (2013) also says “sterilization and disease risk might both be
correlated with specific canine behaviors. Given the opportunity, intact
male dogs are more likely than sterilized dogs to roam, and to fight with
other dogs, and intact female dogs show more dominance aggression than
spayed females. These behaviors might increase the risks of both
infectious and traumatic causes of death among intact dogs” (pg. 5)
o Lastly Hoffman (2013) says “Sterilization increased the risk of death due
to neoplasia, but did not increase risk for all specific kinds of cancer.
Female dogs sterilized before sexual maturity are unlikely to develop
mammary cancer because of the decrease in cumulative estrogen exposure
associated with the absence of the estrus cycle However, it is not clear
why the frequency of some cancers outside the reproductive system,
including lymphoma and osteosarcoma, is influenced by sterilization,
while the frequency of others, such as melanoma and squamous cell
carcinoma, is not. The increased risk of death due to cancer observed in
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sterilized dogs could be due to the fact that in both sexes, dogs sterilized
before the onset of puberty grow taller than their intact counterparts as a
result of reduced estrogen signaling. Recent studies in humans suggest
that growth is a risk factor for a number of different cancers” (pg. 6)
Science News (1997) explains how spaying or neutering early contrary to popular
belief does not actually affect the animal In any way, in this case of study a male
cat by saying “A study in 1991 found no major health differences between dogs
that were neutered at 7 weeks and at 7 months of age” (pg. 45)
o Science News (1997) also says “Cats of both sexes neutered at 7 weeks
showed no significant differences in bone development, body weight, fat,
or behavior from cats neutered at 7 months. Both groups of neutered cats,
at age 1 year, had more generous potbellies than cats that weren't
neutered, and they also seemed to have more generous hearts” (pg. 45)
o Science News (1997) concludes with “neutered cats were significantly
more affectionate and less aggressive than intact animals” (pg. 45)
Ray (2008) a New York Times author writes “If it is done before she comes into
heat, spaying virtually eliminates the risk of breast cancer, the most common type
of cancer in female dogs, she said. In female cats, too, breast tumors are common,
and 90 percent of them are malignant. But a cat spayed before age 2 is one-
seventh as likely to develop them.” (pg. 1)
o Ray (2008) also writes “Spaying also prevents ovarian or uterine cancer,
uterine infections and other diseases. And it cancels the risks associated
with giving birth” (pg. 1)
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o Ray (2008) concludes with “In dogs and cats, males that have not been
neutered are at risk for testicular cancer, prostate disease and hernias,
among other problems. Neutering also often reduces fighting, roaming
and scent marking, behaviors that may land a pet in a shelter, where
euthanasia is a risk” (pg. 1)
Burgess-Jackson (1998) writes in his book “Whatever responsibilities a person
has to one animal he/she has to all the animals as a whole” (pg. 159) He writes
this when explaining when a person owns a dog that they care and love for, they
also have a responsibility for the sake of all the other dogs to train, love, house,
and give medical attention
o Burgess-Jackson (1998) goes on to say in this time our companion are
suffering due to over population, perfectly healthy, and happy dogs are
being euthanized daily, and the one way to prevent this from happening is
by stopping the reproduction of unwanted animals. The way of doing this
is simple; Spaying and neutering. Not only does it benefit our animals but
also the group of animals as a whole (pg. 159)
Lloyd (1987) explains in his book Attitudes Towards Responsible Pet Ownership
that once when companion animals were not domesticated there were ways of
population control, now that we domesticated them we have seen an
overpopulation therefore we need to instill population control we can do this by
“Contributing to an excess number of stray or feral animals are abandoned or
lost pets and uncontrolled matings that result in unwanted young. Preventive
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measures to keep cats and dogs in the pet population include adoption, neutering,
and owner education.” (pg. 380)
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Analysis/ Evaluation
The research gathered above shows a lot about the overall affects of spaying/
neutering companion animals on the individual basis, and a communal basis as well. The
research suggests many implications of why people should make spay/neuter their
companion animals both because of health, and because of current problems. First the
health benefits of the individual animal showed a lot about how effective spay/neutering
is at increasing the longevity of the animal.
Spaying and neutering is something that vets recommend to do at an early age.
New York Time’s author Ray suggests in her research that spaying and neutering as early
as 7 weeks has no detrimental effects on the animals early development physically or
mentally. In fact the animals that were altered the earliest seemed to have the most
healthy and effective hearts. It is believed that when you sterilize an animal early it
affects their development because of the lack of hormones that the reproductive organs
stimulate. The research showed the cats altered at 7 weeks had the same composition, and
physical attributes as the cats altered at 7 months, which suggests that there is no effect in
how early the companion animals are sterilized, and the earlier the better because Ray
also says that female cats can start reproducing at the age of just 6 months old.
The earlier the animals were being sterilized the earlier more the chances went
down for both males and females to develop mammary cancer, a very common and fatal
type of cancer present in many in-tact animals. Research from Hoffman suggests if you
alter your pet as early as 7 weeks the chance of them developing mammary cancer is
virtually none, and chances slightly go up after the 7 week mark because hormones are
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being released into the system. The research also went on to talk about later in the life of
the altered animal.
The animals that were altered in the research from Hoffman, Science News, and
Abrams were shown to live one and a half years longer than the animals that were not.
The animals that were sterilized early were shown to have an average lifespan of a
decade in dog years, over their counter parts. This research was gathered using records of
the deaths of 40,000 dogs and cats. The animals were looked to see if they were sterilized
or not, and than how long they lived, and cause of death. The researched showed that the
dogs that were altered did in fact live longer, but all seemed to die of similar causes,
which for the most part included cancer. Than they looked into the genetics of an altered
animal versus an intact animal which shows that sterilized animals are much more likely
to grow taller, and therefore have greater chances of developing cancer. The main reason
the research suggested the dogs were developing cancer was because of the plain and
simple fact that the dogs were living longer, therefore because of old age were
developing common diseases. The unaltered animals were dying at younger ages than the
altered animals and were mostly dying from autoimmune diseases, cancer, and trauma.
The autoimmune diseases the animals were dying from were looked into. The research
showed that testosterone (in males), and Estrogen (in females), which would be in
increased levels in an intact animal, could actually be immunosuppressant and therefore
cause the animal to be more susceptible to getting a disease that could lead to death. The
cancer the animals were dying from was in a vast amount of the cases was a reproductive
organ. Lastly the trauma that caused a lot of the unsterilized dogs deaths was linked to the
behavior issues that arise with intact dogs.
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Intact dogs have an increase of reproductive hormones surging throughout there
body, were sterilized dogs do not have the hormones because the reproductive units have
been removed from their bodies. Animals that have these hormones are much more likely
to roam; have aggressive tendencies, and overall behavioral problems. The animals that
are more likely to roam are also more likely to suffer trauma like being hit by a car when
they are out of the control of a human. Behavioral problems that arise can be attributed
to animals bring intact, and behavioral problems lead to a person giving an animal up to
an animal shelter. Thus brings in the part of the research that shows how spaying and
neutering is crucial for companion animals as an entire group.
Pet overpopulation is no myth it is a real thing that is happening right now. Lloyd
explains pet overpopulation, the problem we are faced with simply. Companion animals
were not always domesticated by people like they are now. At one point they were wild
animals and in any wild animal population there were means to control the overall
population. These means of control were taken away when we as people domesticated the
animals, and now because we are not controlling the population we have overpopulation.
The solution is simple to this problem, but problem arises people are not willing to solve
the problem, or are uneducated that the problem is happening all around them.
Pet overpopulation has many detrimental effects to both the community of people
and animals. The research from Frank shows the effects of the pet overpopulation on
economy, which is $1 billion dollars spent annually on euthanasia. Also on the
community which is the number of stray dogs, and dog attacks to either a person or
another dog which rack up bills in the millions annually. But the effect of overpopulation
on all the companion animals as a whole is the one that really shows how bad the
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problem truly is. The pet overpopulation gives each shelter about 1000 new dogs per
week, the same number are euthanized to make space for the new ones. The animals that
end up is shelters are given typically 1-2 weeks to find a home before they are put to
death solely for lack of space. These animals are young, healthy, great tempered dogs and
even the older dogs with some health issues that can be easily fixed are being put to death
solely because of lack of space.
These animals are being born into a world with no room where more than half of
their fates are to be put to death before they even get a chance to live out their lives.
Responsible pet owners have an obligation, says Burgess-Jackson, if they take on a pet to
care for them and their whole species, as you are an ambassador for them when you own
one. The solution to this problem is just as easy, and the same as all the other solutions to
all the other multiple problems that are happening to animals both individually and as a
whole, and the solution is spaying and neutering.
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Conclusion
In conclusion the research presented clearly shows that it truly is crucial to the
benefit of an individual level and group level of companion animals to spay and neuter
them. Spaying and neutering increases life span, decreases chances of certain cancers,
decreases chances for behavioral problems. The spaying and neutering of companion
animals does nothing harmful to them, and all in all only affects them positively. The
research proves there are only positive and healthy benefits to sterilizing companion
animals, and the aspects of their life it prevents such as illness, and behavioral problems
contribute to the immense problem of pet overpopulation, which is also prevented by
spaying and neutering.
Research shows that pet overpopulation is a major problem, but that is easily seen
by the rate of euthanasia of healthy animals throughout the country. Pet overpopulation is
due to the domestication of companion animals with no means of controlling the rate of
population. This has lead to millions of animals being homeless, and put to death due to
lack of space. The unsterilized animals are the ones who most end up in the shelters
because they are much more likely to have behavioral problems, and are much more
likely to roam and run off in search of fulfilling their drive to reproduce due to hormones.
The only way to control the problem of pet overpopulation is to spay and neuter animals
to prevent them from being born into a world without a home. All in all the research
suggests that for the reasons of health, behavior, and longevity to the affects of
controlling overpopulation, and overall benefits to the individuals and the whole group of
companion animals, it is crucial to spay and neuter all companion animals
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Bibliography
Abrams, L. (2013, April 19). Study: Spayed and Neutered Dogs Live Longer. The
Atlantic. Retrieved May 7, 2013, from
http://www.theatlantic.com/health/archive/2013/04/study-spayed-and-neutered-
dogs-live-longer/275121/
Biology [Abstract]. (1997). Science News, 151(3), 45-45. Retrieved May 8, 2013, from
http://www.jstor.org/stable/3980684
BioMedicine [Abstract]. (1994). Science News, 145(25), 399-399. Retrieved May 8,
2103, from http://www.jstor.org/stable/3977963
Budiansky, S. (1999, July). The Problem With Breeding. The Atlantic. Retrieved May,
2013, from http://www.theatlantic.com/past/docs/issues/99jul/9907dogs3.htm
Burgess-Jackson, K. (1998). Doing Right by Our Animal Companions [Abstract]. The
Journal of Ethics, 2, 2nd ser., 159-185. Retrieved May 8, 2013, from
http://www.jstor.org/stable/25115576
Carroll, M. (2013, May 6). Out-of-control cat population leading to
euthanasia.Washington Post. Retrieved May 7, 2013, from
http://www.washingtonpost.com/local/out-of-control-cat-population-leading-to-
euthanizations/2013/05/01/cf3a5c5c-b292-11e2-9fb1-62de9581c946_story.html
Frank, J. (2004). An Interactive Model of Human and Companion Animal Dynamics:
The Ecology and Economics of Dog Overpopulation and the Human Costs of
Addressing the Problem. Human Ecology, 32(1), 107-130. Retrieved from
http://www.jstor.org/stable/4603504
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Hoffman, J. M., Creevy, K. E., & Promislow, D. E. (n.d.). Reproductive Capability Is
Associated with Lifespan and Cause of Death in Companion Dogs. Retrieved May
8, 2013, from
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.006108
2
Klinkenborg, V. (2007, July 30). Should Most Pet Owners Be Required to Neuter Their
Animals? The New York Times. Retrieved May 7, 2013, from
http://www.nytimes.com/2007/07/30/opinion/30mon4.html?_r=0
Lee, J. (2009, February 26). Spay and Neuter Program Fights Pet Abandonment. City
Room Spay and Neuter Program Fights Pet Abandonment Comments. Retrieved
May 7, 2013, from http://cityroom.blogs.nytimes.com/2009/02/26/spay-and-
neuter-program-fights-pet-abandonment/
Ray, C. (2008, May 20). Giving Pets Long Lives. Washington Post. Retrieved May 8,
2013, from http://www.nytimes.com/2008/05/20/science/20qna.html?_r=0
Selby, L. A. (1979). A Survey of Attitudes toward Responsible Pet Ownership. Public
Health Reports (1974-), 94, 4th ser., 380-386. Retrieved May 7, 2013, from
http://www.jstor.org/stable/4596127
