Thursday, July 12, 2018

The Trouble with Cats

Charles Danten, former veterinarian

Every single person that’s worth knowing on this planet is a cat lover. Ex Canadian Prime Minister Harper loves cats, Oprah loves cats, Paul McCartney loves cats, my friends love cats, and so do I. 

Unfortunately, cat love is not without consequences...


These purring machines that we love to cuddle and pet are carriers of toxoplasmosis, a parasitic disease transmitted exclusively by the feces of cats (1). Because of our good doing, this common protozoan disease is now found in bottlenose dolphins, walruses, sea otters, and as far North as the Arctic belugas. (2)(3)

Toxoplasma gondii is especially dangerous for the immunocompromised like stressed-out people, the elderly, and those with chronic diseases such as diabetes and HIV. Pregnant women are particularly at risk. The parasite is also dangerous for young children because of their tendency of sticking their fingers in their mouth or eating soil (geophagia). (4) In 2015, scientists, E. Fuller Torrey, Wendy Simmons, and Robert H. Yolken confirmed a long established but controversial link between this parasite and several serious mental conditions such as schizophrenia, bipolar disorder, and obsessive-compulsive disorders (OCD) (hoarding, for example, is an OCD). (5)(6)

According to these scientists, owning a cat during childhood may increase, significantly, the risk of contracting these conditions later. (7) This study is still subject to caution, it has to be corroborated by further studies, but if I were a cat lover, I would not take this finding lightly. The prevalence of toxoplasmosis is unknown since it is not a reportable disease, but because of the HIV epidemic, we now know that authorities grossly under evaluated the importance of animal transmitted diseases such as toxoplasmosis. (8)

To fully grasp the extent of the danger, it helps to know that this parasite is difficult to detect due to its small size and its intermittent and unpredictable shedding in the feces. A routine stool analysis by the veterinarian is therefore likely to be negative. It also helps to know that this parasite is widely spread. 

American stray cats, for instance, which are reservoirs of this disease, deposit in the environment approximately 1.2 million metric tons of excrement per year, or 520 Olympic swimming pools full. (9) And that’s without counting the countless quantities of cat stool flushed in toilets and the humongous amounts of soiled litter, which are systematically trashed by cat owners, without any second thought. On the basis of 2 kg of litter per week, the 1.5 million cats or so of Quebec use 156 000 metric tons of litter per year or roughly 75 Olympic pools full. 

Please, do not dump your cat. Just be extra careful. Wear gloves when you change the litter of your cat or when you work with soil. Wash your hands after handling your cat. Wash your fruits and vegetables carefully. If you are pregnant, stay away from cats and gardening altogether. Make sure your children do not play where cats are known to roam. In cities, that would be everywhere. According to a Canadian Broadcasting Corporation article posted on the web, in 2010, in the Montreal Côte-Saint-Luc neighbourhood alone, for example, there were approximately 10 000 homeless cats. (10)

Other diseases transmitted by cats

Cats are also the most important vectors of rabies in North America. In 2013, at Point Pleasant Beach, N.J., authorities had to destroy a colony of feral cats because several rabid animals were attacking children. (11) 

These outcasts of society also transmit to wild cats such as the lynx and the mountain lion, species endemic to Canada and the US, killer diseases like feline leukaemia, panleukopenia, and feline immunodeficiency syndrome. (12)

But disease transmission is not the only problem with cat love.

Effects on the environment

According to a major American study published in 2013 by scientists Scott R. Loss, Tom Will, and Roger P. Mara, feral cats (domestic cats returned to the wild) and domestic cats on the loose are the most important cause of anthropogenic mortality of birds and mammals. (13)(14)(15) Indeed, in the United States alone, these fearsome predators kill between 1.4 to 3.7 billion birds and 6.9 to 20.7 billion small mammals per year. (16) In Australia, the twelve million feral cats that roam the country are partially or totally responsible for the disappearance of at least 28 animal species. (17) These born killers are serious problems, especially on islands. The land iguanas of the Turks and Caicos Islands, for example, were decimated in just six years. (18) New Zealand is also plagued, with a vengeance, by this unpredicted side effect of feline love, which is affecting every Western nation of the world. (19) And Canada by all means has not been spared by this predator mayhem.

However, despite this disastrous assessment which should theoretically dampen this unbridled passion for cats, good Samaritans who feed colonies of stray cats are strongly opposed to their capture and euthanasia for what amounts to be selfish reasons when you think about it. Most of these animals live a miserable life plagued by wounds, disease, malnutrition, and in cold countries such as Canada, hypothermia. (20)(21)

In America, perceived as the most progressive country in the world, cat worshippers funded by various lobby groups that profit from the pet business and assisted by an army of lawyers specialized in Animal rights – the new gold mine of the law profession – are ready to defend to the last breath these hapless victims of love, regardless of the consequences on nature and people. (22)(23) 

Trap-Neuter Release program

Advocates of the Trap-Neuter-Release program (TNR), with the help of veterinarians and the SPCA, who have joined the battle for "right to live" and humane reasons, stubbornly refuse to admit that TNR aggravates the problem. Yet, the number of cats that are actually recycled by TNR is insignificant compared to the large number of feral cats that would have to be recycled (60 million in the US). And it's a lost battle from the start, because many cats are refractory to trapping and many new cats are constantly being abandoned. TNR in addition has absolutely no effect on the destruction of indigenous species, pollution, and the spread of diseases. (24)(25)(26)

The “right to live” argument

The “right to live” argument cannot be blindly applied to animals. Unlike humans, cats are unaware of their impeding death. They can certainly be terrified about the whole capture procedure, but they don’t have a clue about what follows. In other words, without a symbolic language like ours, felines cannot know whether they are trapped to be sterilized under anaesthesia and released or whether they are trapped to be euthanized. There is therefore no logical reason not to euthanize these animals for their own good, the good of the environment, and the good of humans. 

Other solutions

Australian authorities were totally immune to the ranting and raving of Brigitte Bardot and other cat worshippers. (27) The promoters of this ultra-sophisticated system, which built its animal policies around the dubious theories of Peter Singer and Boris Levinson decided to take the matter into their own hands. For hygienic reasons and to protect its seriously threatened fauna, Australia will eradicate several million stray cats in the coming years. (28)

In New Zealand, ecologists of the Gareth Morgan Foundation took the matter one step further than the Australians by recommending as well... to stop adopting cats. (29)

On a strictly evolutionary, ethical, and commercial basis, it is the right thing to do.


1. E. Fuller Torrey and Robert H. Yolken (2013). Toxoplasma oocysts as a public health problem. Trends in Parasitology; 29 (8): 380-384. 

2. Brenda McGregor (2014). Cat Parasite Infects Arctic Belugas:

3. N Massie, Gloeta & Ware, Michael & Villegas, Eric & Black, Michael. (2010). Uptake and transmission of Toxoplasma gondii oocysts by migratory, filter-feeding fish. Veterinary parasitology. 169. 296-303. 10.1016/j.vetpar.2010.01.002. 

4. F. G. Angulo et al. (1995). Caring for pets of immunocompromised persons. Canadian Veterinary Journal; 49: 217-222.

5. E. Fuller Torrey, Wendy Simmons, and Robert H. Yolken (2015). Is childhood cat ownership a risk factor for schizophrenia later in life? Schizophrena Research; 165(1): 1-2.

6. Fond G. et al. (2012). Toxoplasma gondïi : un rôle potentiel dans la genèse de troubles psychiatriques. Une revue systématique de la littérature. Encéphale.

7. E. Fuller Torrey, Wendy Simmons, Robert H. Yolken (2015). Art. cited.

8. F. G. Angulo et al. Art. cited.

9. E. Fuller Torrey and Robert H. Yolken (2013). Art. cited.  

10. David Gentile (2010). La chasse aux chats errants. Société Radio Canada

11. R. Zeuner, S. Lopez, A. Link, S. Muehlhausen, and M. Chaney (2013). Predator Mayhem. New Mexico Supercomputing Challenge Final Report.

12. Scott R. Loss, Tom Will, and Roger P. Mara. (2013). The impact of free-ranging domestic cats on wildlife of the United States. Nature Communications4: 13-96.

13. Hawkins, C. C. et al. (2004). Effect of house cats, being fed in parks, on California birds and rodents. Proceedings 4th International Urban Wildlife Symposium.

14. R. Zeuner, S. Lopez, A. Link, S. Muehlhausen, and M. Chaney. Art. cited.

15. Scott R. Loss, Tom Will, and Roger P. Mara. Art. cited.

16. Ibid.

17. The Feral Cat (Felis Catus) (2015). Australian Government. Department of Sustainability, Environment, Water, Population and Communities. 

18. Bruce. E. Collentz (1998). Étrangers au paradis: mammifères envahissants dans les îles. Planet Conservation.

19. Gareth Morgan (2015). Cats to go. That little ball of fluff you own is a natural-born killer. Gareth Morgan Foundation. New Zealand.

20. Ted Williams (March 14 2013). Trap, neuter, return programs make feral cat problem worse. Orlando Sentinel.

21. Jim Sterba (2012). Feral Felines. Nature Wars. Broadway Books.

22. Ted Williams. Art. cited.

23. Lohr C.A. et al (2012). Costs and Benefits of Trap-Neuter-Release and Euthanasia for Removal of Urban Cats in Oahu, Hawaii. Conservation Biology.

24. Ibid.

25. Ted Williams. Art. cited.

26. Jim Sterba. Work cited.

27. Hilary Hanson (2015). Brigitte Bardot Slams Australia's Plan To Kill 2 Million Feral Cats “Inhumane and ridiculous.” The World Post.

28. Australian Government. Art. cited. 32. 

29. Gareth Morgan (2015). Cats to go. That little ball of fluff you own is a natural-born killer. Gareth Morgan Foundation. New Zealand.