PRoblems & Cost
Disease
Feral cats contribute to the spread of many diseases, even some which are zoonotic. In 2010, a feral cat colony was the source of hookworm infections in several people living in South Florida. Hookworms are zoonotic and can infect people and other pets through contact with skin, so just walking barefoot can leave one susceptible to this parasite1.
Rabies, ringworm, tularemia, plague, and toxoplasmosis are other issues that feral cats transmit to other wildlife or humans. Several of the diseases associated with feral cats can cause health issues in humans, including abortion, blindness, lack of focus, skin rashes, and various other ailments. In fact, approximately one third of human exposure to rabies can be associated with cat bites1.
Additionally, feral cats contribute to the spread of the Feline Leukemia Virus (FeLV) and Feline Immunodeficiency Virus (FIV). FeLV is easily spread when an uninfected cats comes into contact with the saliva or urine of an infected cat. This can be through mutual grooming, sharing of food/bowls, nose-to-nose contact, or fighting. FIV is more difficult to spread, as it is transferred only through blood. The most common activity which transfers the disease is fighting. A feral cat which is captured and tested for FeLV or FIV is typically euthanized2.
Feral cats contribute to the spread of many diseases, even some which are zoonotic. In 2010, a feral cat colony was the source of hookworm infections in several people living in South Florida. Hookworms are zoonotic and can infect people and other pets through contact with skin, so just walking barefoot can leave one susceptible to this parasite1.
Rabies, ringworm, tularemia, plague, and toxoplasmosis are other issues that feral cats transmit to other wildlife or humans. Several of the diseases associated with feral cats can cause health issues in humans, including abortion, blindness, lack of focus, skin rashes, and various other ailments. In fact, approximately one third of human exposure to rabies can be associated with cat bites1.
Additionally, feral cats contribute to the spread of the Feline Leukemia Virus (FeLV) and Feline Immunodeficiency Virus (FIV). FeLV is easily spread when an uninfected cats comes into contact with the saliva or urine of an infected cat. This can be through mutual grooming, sharing of food/bowls, nose-to-nose contact, or fighting. FIV is more difficult to spread, as it is transferred only through blood. The most common activity which transfers the disease is fighting. A feral cat which is captured and tested for FeLV or FIV is typically euthanized2.
Impacts on Wildlife and Surrounding Ecosystems
Feral cats can outcompete native predators and change the composition of the ecosystem3. Studies have shown that when feral cat populations are large, there are large amount of exotic rodents but few native rodents. It is predicted that native rodents cannot survive in environments where they are outnumbered by predators4. Specifically on insular ecosystems, feral cats can be attributed to the extinction of species. In Australia alone, it is estimated that over 100 species are currently threatened by the presence of feral cats5.
Just in the United States, feral and free-ranging cats are the largest source of human-influenced mortality for birds and small mammals6.
Feral cats can outcompete native predators and change the composition of the ecosystem3. Studies have shown that when feral cat populations are large, there are large amount of exotic rodents but few native rodents. It is predicted that native rodents cannot survive in environments where they are outnumbered by predators4. Specifically on insular ecosystems, feral cats can be attributed to the extinction of species. In Australia alone, it is estimated that over 100 species are currently threatened by the presence of feral cats5.
Just in the United States, feral and free-ranging cats are the largest source of human-influenced mortality for birds and small mammals6.
7Total cost to eradicate all feral cats |
Total cost of TNR programs to sterilize all feral cats |
Total cost of TNR programs if veterinarians and clinics donated time |
15.74 |
14 |
6.9 |
billion |
billion |
billion |
US alone |
US alone |
US alone |
- Gerhold, R.W., & Jessup, D.A. 2012. Zoonotic diseases associated with free-roaming cats. Zoonoses and Public Health. 60(3), 189 - 195.
- Slater, M. (2002). Community Approaches to Feral Cats. Washington, DC: Humane Society Press.
- Crooks, K.R., & Soule, M.E. (1999). Mesopredator release and avifaunal extinctions in a fragmented system. Nature, 400, 563 - 566.
- Loyd, K.A., & Miller, C.A. (2010). Factors related to preference for trap-neuter-release management of feral cats among Illinois Homeowners. The Journal of Wildlife Management, 74(1), 160 - 165.
- Mitchell, S. (2015). One of the world's biggest extinction crises is being caused by cats. Vice News.
- Loss, S.R., Will, T., & Marra, P.P. (2013). The impact of free-ranging domestic cats on wildlife in the United States. Nature Communications, 4.
- Nolen, R.S. (2010). Economic study estimates costs of feral cat control. Journal of American Veterinary Medicine Association.