The Harmful Effects of Free Range Cats
The Harmful Effects of Free Range Cats
by: Caitlin Grimes and Allie Orberson
Introduction
It is not uncommon for cat owners to let their domesticated cats free-roam the outdoors. Owners justify this practice by claiming their cat is bored indoors or being outdoors allows their cat to follow its natural hunter instincts. Yet cat owners fail to recognize how allowing domesticated cats to free-roam is detrimental to the environment and to the health of the cat and humans.
Domestic free-roaming cats are skilled, yet wasteful, predators that kill billions of native birds and other small mammals per year for food and for play.[1],[2]While roaming, cats will encounter a number of life-threatening dangers. Additionally, allowing a pet cat to roam the outdoors poses greater health risks to the owner of the cat. Free-roaming cats have a higher likelihood than indoor cats of contracting an infectious disease and jeopardizing the health of its owner.[3]
Background
Frequently, people forget that domesticated cats and their feral relatives are not native predators in North America. In the 1600s, settlers to the new world brought rats, disease, and a new furry predator.[4] Domestic cats have been listed in the top 100 worst invasive species in the world.[5]It should be unsurprising that some 400 years after cats initial debut to the “New World,” cats wreaked havoc on their new ecosystem primarily to the smaller prey such as lizards, mice, and birds.[6]
Since the 1600s, owners of cats continue to allow and encourage their cats to peruse the great-outdoors. It is common knowledge that cats are fierce predators and in fact will frequently bring bird carcasses to the doorstep of their home. Yet, people still do not seem to understand the detrimental effect their fluffy friends are causing in the greater ecosystem. In a prior survey conducted by the American Bird Conservancy organization, only 35% of the sample group kept their cat inside all the time and 49% responded they would keep their cat indoors if it were beneficial to wildlife.[7]The American Bird Conservancy (ABC) concluded that people still believe it is necessary for cats to have the freedom to roam.[8]
Issue
In the United States free-ranging domestic cats kill approximately 1.3-4.0 billion birds every year.[9]Studies show approximately thirty-three bird species have gone extinct because of cats since their introduction.[10] This number is likely a conservative approximation because it accounts only for the clear and direct extinctions caused by cats.[11] Under the theory of predation in the landscape as a whole, which considers what extinctions and deaths have been caused by the cat’s intimidation, further stress on the environment, and disease spreading – thirty-three extinctions is likely a much smaller kill count than cats are owed credit for.[12]
While keeping cats indoors protects the environment, it also protects the cat from life threatening dangers it is likely to encounter while free roaming. The Humane Society of the United States estimates a typical lifespan of a roaming cat to be only five years, whereas indoor cats typically live up to seventeen years.[13]While most cats will instinctively find their way home, a study found that 15% of cats reported missing will never return home to their beloved owner.[14]A lost pet is gut-wrenching and owners of missing cats are often guilt ridden for allowing their cat to free roam to begin with. There are many possible scenarios that may inhibit a cat from returning home.
First, humans inadvertently create hazards for free roaming cats. Cats can fall victim to cars, poison, and animal traps. Also, cats become territorial over familiar areas and are likely to engage in altercations with other cats and animals, especially if the cat is not neutered or spayed. Even friendly altercations may cause an unexpected burden on a cat owner because unspayed female cats face the risk of an accidental pregnancy. One intact female cat is capable of producing a dozen kittens per year.[15]If those kittens grow up and breed themselves, thousands of kittens will be born over the years, contributing to the overpopulation of cats. The likelihood of finding each accidental kitten a safe home is low, especially considering the lack of socialization each kitten will receive. Moreover, altercations with other cats or animals can turn south leading to fights which may cause serious injuries including lacerations, bites, broken bones, transmission of infectious diseases, or even death.[16]Insects, such as fleas and ticks, also contribute to the transmission of infectious diseases in cats, such as lyme disease. Not only are disease-ridden cats uncomfortable themselves, but the cats pose health risks to humans as well.
Public health officials have concerns about the possible transmission of diseases to humans, including the plague, rabies, toxoplasmosis, lyme disease, and encephalitis.[17]Of these five, rabies is the most common. Feral cats are susceptible to contracting feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV).[18]FIV and FeLV-infected cats are at an increased risk of contracting rabies and the risk of infection for pet cats that are allowed outside is significantly higher than that of strictly indoor pet cats.
Additionally, the toxoplasmosis infection rate has been shown to be higher in free-roaming cats and outdoor pet cats than strictly indoor cats. Scientists have identified that as many as 74% of adult domestic cats have been infected by the parasitic protozoan Toxoplasma gondii, which causes toxoplasmosis, at some point in their lifetime.[19]Cats become infected with toxoplasmosis by eating infected rodents, birds, or other small animals, or anything contaminated with feces from another cat that is shedding the microscopic parasite in its feces.[20]Humans can become infected in several ways including accidental ingestion of oocysts after eating food, drinking water, or swallowing soil that has been contaminated with infected cat feces.[21]Eating raw or undercooked meat from infected animals or cleaning a toxoplasmosis-infected cat’s litter box will also spread toxoplasmosis to humans.
Most people who become infected with toxoplasma do not show symptoms and when illness occurs, it is typically mild.[22]However, illness may be severe, having impacts on humans such as spontaneous abortion for pregnant women, fetal developmental defects, blindness, and neurological impairment.[23]Additionally, toxoplasmosis can create cysts in the central nervous system that can cause an increased chance of schizophrenia, autism, Alzheimer’s, and other neuro-inflammatory diseases.[24]
Resolution
The harms caused by free-range cats are traceable results from irresponsible pet ownership and a lack of effective control on feral cat populations. These distinct contributing factors require unique specific tactics to overcome the harm caused and one overarching solution: not allowing cats to freely roam.
The most obvious solution to curing the harms caused by free-roaming cats is to keep the cats as strictly indoor pets.[25]The ABC in a telephone survey noted that some of the cat owners allowed their cat to roam because they were not fully committed to having the cat as a pet.[26]This irresponsible pet ownership coupled with the lack of understanding the harm caused by roaming cats can be cured with education regarding “responsible cat ownership.” The ABC has been a constant advocate in encouraging responsible ownership to the benefit of communities, the environment, and the cats themselves.[27]In sum, the best solution to curbing harm caused by free-roaming cats is to advocate for responsible pet ownership which includes, keeping cats indoors, on leashes outdoors, and encouraging other cat owners to do the same.
Unfortunately, even if all cat owners kept their pet from free roaming, the problem would not be immediately solved. Euthanasia of stray and feral cats is the end result for thousands of cats as local shelters cannot find enough homes and the offspring of stray cats are not properly socialized for adoption.[28]
Beginning in the 1990s, coalitions of people concerned for the welfare and wellbeing of stray and feral cats set out to promote feline welfare by implementing nonlethal methods of population control.[29]Trap/Neuter/Release (TNR) programs were introduced as an alternative to euthanasia, which operate by first trapping feral cats, who are then spayed or neutered before being released into designated cat colony areas located on private and public land.[30],[31]Supporters of TNR initiatives theorize that these programs help to slowly reduce the feral cat population over time through the euthanasia of unhealthy cats, placement of adoptable cats, and the death of cats from natural causes.[32]However, research indicates that TNR programs do the opposite, and that feral cat populations may actually increase in size, rather than slowly disappearing.[33]
Unfortunately, TNR sites are frequently mismanaged, and subsequently, the cat population increases. A TNR program’s efficacy depends on volunteers, financial resources, low-cost neutering and spaying services, location of the site, and local cat control ordinances.[34]Unlike natural ecological systems, TNR programs promote an increase in the carrying capacity because cat colony caretakers continually provide food for the colony, thereby preventing the population from a natural chance to “even out” and encouraging new stray cats to immigrate into the colony.[35]Additionally, conservationists have found that unscrupulous cat owners abuse the designated feral cat colony areas by releasing their unwanted cats.[36]As a result, breeding and recruitment within the cat colonies persist, and the population does not decline as expected. Further, TNR programs do not save the cats from the varied risks posed to the cat’s safety.[37]
Although TNR programs are not a perfect solution, many advocates argue that TNR programs are more humane than euthanasia. TNR’s success is largely dependent on a myriad of factors. Namely, local governments must be willing to allocate sufficient resources and the volunteers must be adequately trained to ensure successful TNR sites. Concurrently, TNR sites should never be in parks or recreational areas. If the location is in a public area, then the problems associated with roaming cats are compounded.[38]Furthermore, the local government must pass sufficient ordinances to ensure the cat populations decrease.[39]These variables will likely continue to be a difficult mark for the majority of communities to achieve, especially in areas with dense cat populations.[40]
At first glance, TNR programs seem to be ideal. However, the programs are difficult to implement and manage successfully. In sum, a mixed approach of euthanasia and TNR programs, when appropriately managed, is necessary to truly overturn the hurdles posed by the ever-increasing stray/feral cat population.
Conclusion
In conclusion, free roaming cats have a devastating effect on the ecological world around them, especially on bird populations. Additionally, the roaming cats haphazardly promote public health concerns among its species and to humans. As a collective group, cat owners must consciously take the necessary steps to educate themselves and others on ways to protect their feline friends and the environment.
[1]American Bird Conservancy, The American Bird Conservancy’s Resolution on Free-Roaming Cats, (1997),https://abcbirds.org/wp-content/uploads/2019/01/1997.9-ABC_Resolution-on-Free-roaming-Cats.pdf.
[2]Grant Sizemore, Do A Little, Save A Lot: Keep Cats Indoors, (2005), Louisiana-Ornithological-Society-Newsletter-Winter-2015.pdf (abcbirds.org)(see also Report_The_Science_of_Feral_Cats.pdf (abcbirds.org)
[3]Grant Sizemore, Report the Science of Feral Cats,American Bird Conservancy, https://abcbirds.org/wp-content/uploads/2015/05/Report_The_Science_of_Feral_Cats.pdf
[4]Linda Winters & George Wallace, Impacts of Feral and Free-ranging Cats on Bird Species of Conservation Concern, (2006)https://abcbirds.org/wp-content/uploads/2015/07/NFWF.pdf.
[5]Lowe S. et.al.. 100 of the World’s Worst Invasive Alien Species: a Selection from The Global Invasive Species DatabaseInvasive Species Specialist Group, International Union for Conservation of Nature (2000).
[6]Loss, S. et. al., The impact of free-ranging domestic cats on wildlife of the United States.Nat Commun 4, (2013), https://doi.org/10.1038/ncomms2380The impact of free-ranging domestic cats on wildlife of the United States | Nature Communications
[7]American Bird Conservancy, Human Attitudes and Behavior on Keeping Cats Indoors,(2012), https://abcbirds.org/wp-content/uploads/2015/05/Human_Behavior2012.pdf
[8] Id.
[9]Loss, S. et. al., The impact of free-ranging domestic cats on wildlife of the United States.Nat Commun 4, (2013), https://doi.org/10.1038/ncomms2380The impact of free-ranging domestic cats on wildlife of the United States | Nature Communications
[10] Linda Winters & George Wallace, Impacts of Feral and Free-ranging Cats on Bird Species of Conservation Concern, (2006)https://abcbirds.org/wp-content/uploads/2015/07/NFWF.pdf.
[11]Id.
[12]Colin Bonnington, et.al, Fearing the feline: domestic cats reduce avian fecundity through trait-mediated indirect effects that increase nest predation by other species, Journal of Applied Ecology (2013), https://abcbirds.org/wp-content/uploads/2015/07/Bonnington-et-al.-2013-Domestic-cats-reduce-avian-fecundity-through-indirect-effects.pdf.
[13]American Bird Conservancy, The Great Outdoors is No Place for Cats, https://abcbirds.org/wp-content/uploads/2015/05/GreatOutdoors2011.pdf
[14]Arden Moore, What Are the Chances of Finding My Lost Pet? ASPCA Survey Has the Answers, VetStreet, (2012), http://www.vetstreet.com/our-pet-experts/what-are-the-chances-of-finding-my-lost-pet-aspca-survey-has-the-answers
[15]Susan Paretts, Cat Health:On Average How Many Kittens Can One Cat Have in a Year, The Nest, https://pets.thenest.com/average-many-kittens-can-one-cat-one-year-7043.html
[16]Central California Society for the Prevention of Cruelty to Animals, Top 3 Dangers to Be Aware of When Letting Cats Outside, (2020), https://www.ccspca.com/blog-spca/education/letting-cats-outside/
[17]Daniel Castillo & Alice L. Clarke, Trap/Neuter/Release Methods Ineffective in Controlling Domestic Cat “Colonies” on Public Lands, Natural Areas Journal (2003), https://abcbirds.org/wp-content/uploads/2015/07/Castillo-and-Clarke-2003-TNR-ineffective-in-controlling-cat-colonies.pdf
[18]Grant Sizemore, Report the Science of Feral Cats,American Bird Conservancy, https://abcbirds.org/wp-content/uploads/2015/05/Report_The_Science_of_Feral_Cats.pdf
[19]A.M. Tenter, et. al., Toxoplasma gondii: from animals to humans, International Journal for Parasitology (2000).
[20]Centers for Disease Control and Prevention, Toxoplasmosis: An Important Message for Cat Owners, https://www.cdc.gov/parasites/toxoplasmosis/resources/printresources/catowners_2017.pdf
[21]Id.
[22]Centers for Disease Control and Prevention, Toxoplasmosis: An Important Message for Cat Owners, https://www.cdc.gov/parasites/toxoplasmosis/resources/printresources/catowners_2017.pdf
[23]A. Fekadu, et. al., Toxoplasmosis as a cause for behavior disorders: overview of evidence and mechanisms, Folia Parasitologica (2010).
[24]J. Prandota, Autism spectrum disorders may be due to cerebral toxoplasmosis associated with chronic neuro-inflammation causing persistent hypercytokinemia that resulted in an increased lipid peroxidation, oxidative stress, and depressed metabolism of endogenous and exogenous substances, Research in Autism Spectrum Disorders (2010).
[25]Grant Sizemore, Do a Little, Save A Lot: Keep Cats Indoors, ABC, (2015), https://abcbirds.org/wp-content/uploads/2015/05/Louisiana-Ornithological-Society-Newsletter-Winter-2015.pdf
[26]American Bird Conservancy, Human Attitudes and Behavior on Keeping Cats Indoors,(2012), https://abcbirds.org/wp-content/uploads/2015/05/Human_Behavior2012.pdf
[27]American Bird Conservancy, The American Bird Conservancy’s Resolution on Free-Roaming Cats, (1997),https://abcbirds.org/wp-content/uploads/2019/01/1997.9-ABC_Resolution-on-Free-roaming-Cats.pdf.
[28]Linda Winters & George Wallace, Impacts of Feral and Free-ranging Cats on Bird Species of Conservation Concern, (2006)https://abcbirds.org/wp-content/uploads/2015/07/NFWF.pdf.
[29] American Bird Conservancy, Trap, Neuter, Release,(2021), https://abcbirds.org/program/cats-indoors/trap-neuter-release/
[30]Id.
[31]Linda Winters & George Wallace, Impacts of Feral and Free-ranging Cats on Bird Species of Conservation Concern, (2006)https://abcbirds.org/wp-content/uploads/2015/07/NFWF.pdf.
[32]See, The Cat Network,https://thecatnetwork.org/about/.
[33]Daniel Castillo & Alice L. Clarke, Trap/Neuter/Release Methods Ineffective in Controlling Domestic Cat “Colonies” on Public Lands, Natural Areas Journal (2003), https://abcbirds.org/wp-content/uploads/2015/07/Castillo-and-Clarke-2003-TNR-ineffective-in-controlling-cat-colonies.pdf
[34]Id.
[35]The carrying capacity of a local system may be determined by the limitation of food, water, shelter, etc. Grant Sizemore, Report the Science of Feral Cats,American Bird Conservancy, https://abcbirds.org/wp-content/uploads/2015/05/Report_The_Science_of_Feral_Cats.pdf
[36]Daniel Castillo & Alice L. Clarke, Trap/Neuter/Release Methods Ineffective in Controlling Domestic Cat “Colonies” on Public Lands, Natural Areas Journal (2003), https://abcbirds.org/wp-content/uploads/2015/07/Castillo-and-Clarke-2003-TNR-ineffective-in-controlling-cat-colonies.pdf
[37]Linda Winters & George Wallace, Impacts of Feral and Free-ranging Cats on Bird Species of Conservation Concern, (2006)https://abcbirds.org/wp-content/uploads/2015/07/NFWF.pdf.
[38]Linda Winters & George Wallace, Impacts of Feral and Free-ranging Cats on Bird Species of Conservation Concern, (2006)https://abcbirds.org/wp-content/uploads/2015/07/NFWF.pdf.
[39]Daniel Castillo & Alice L. Clarke, Trap/Neuter/Release Methods Ineffective in Controlling Domestic Cat “Colonies” on Public Lands, Natural Areas Journal (2003), https://abcbirds.org/wp-content/uploads/2015/07/Castillo-and-Clarke-2003-TNR-ineffective-in-controlling-cat-colonies.pdf
[40]Linda Winters & George Wallace, Impacts of Feral and Free-ranging Cats on Bird Species of Conservation Concern, (2006)https://abcbirds.org/wp-content/uploads/2015/07/NFWF.pdf.