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What are the hazards for cats?

What are the hazards for wildlife?

What’s happening in Ontario?

What are outdoor cats up against?

Weighing the options: risks and benefits of letting your pet cat outside

It’s true -- a lot of people let their cats outdoors. At first glance, it may not seem like a problem. Cats enjoy the sunshine and freedom to roam as they please, and many cats return home unscathed after spending time outside, but there is more to this situation than meets the eye. Cats face many serious risks to their health and well-being outdoors, and they also cause serious harm to wildlife and interfere with wild ecosystems.

Hazards for Cats

Outdoor cats face many dangers: predation by other animals, vehicles, human cruelty, and exposure to poisonous chemicals and debilitating diseases (read more about the dangers outdoor cats face here.)

Outdoor cats can also get lost or picked up by other people. Toronto bylaws do not protect cats who roam free on private property; a cat owner's neighbour has the legal right to trap a cat that is digging or defecating around their yard. As a result of these dangers, the average life span of outdoor cats is considerably shorter than that of indoor cats. The average life of an outdoor cat is under five years, more than ten years less than their indoor counterparts. Because of health risks, two out of three veterinarians recommend keeping pet cats indoors1.

To make matters worse, breeding by outdoor cats who are not spayed or neutered contributes to an already booming stray or feral cat population. By some estimates there are many millions of cats without homes in North America. These homeless cats are usually poorly nourished, afflicted by illness, and forced to fight daily for survival.

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Hazards for Wildlife

Outdoor cats have a devastating effect on wildlife populations. U.S. research estimates that outdoor cats annually kill more than a billion birds and small mammals of both common and rare species. Outdoor cats, including those that are well fed, kill many animals that their owners are never aware of -- multiple studies have found feathers and bones in the feces of cats whose owners report their cat has not brought home any animals.

Animals who escape from cat attacks are not as lucky as they may seem. A wound that’s too minor to be visibly detected can still transfer bacteria, resulting in serious infection that will kill an animal even after it has “gotten away.” Even with expert care from qualified wildlife rehabilitators, animals attacked by cats have a very poor survival rate.

While it may be instinctual for cats to hunt, they are a domestic, non-native predator. This means that wild species have not developed defenses against cat predation, and there is no “natural” role for domestic cats in the wild. When cats prey on wild birds and small mammals, it takes food away from wild predators that depend on those animals as a food source. Some wild bird populations have been completely wiped out because of predation from free-roaming cats, and the survival of many other species is currently threatened.

Even if every outdoor cat killed only a few animals a year (though research has shown many cats kill a lot more than a few), the impact is still devastating because of the sheer number of cats. With estimates of over 100 million outdoor cats in North America, the threat to wildlife is simply immense.

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What’s Happening in Ontario?

The cities and towns in Ontario are teeming with outdoor cats. Many outdoor cats end up at municipal animal control shelters or humane societies, which are overflowing with more cats than they have resources to care for. Pet cats contribute significantly to the outdoor cat population – they frequently become lost, or are trapped and removed when they trespass on private property, or have unwanted litters because they aren’t spayed or neutered. Only about 30% of cats in the Greater Toronto Area that wind up in animal shelters are adopted; virtually all the rest are euthanized because they cannot be placed. Only 4% of owned cats that are admitted to shelters across Canada are reunited with their owners2.

Kind-hearted cat lovers have tried to improve upon existing adoption services for cats by creating volunteer-run cat rescue organizations. There are about a dozen of such organizations in the Greater Toronto Area, each of which are also overrun with cats that need homes. Although these groups work in addition to city-run shelters, they still struggle to stay afloat on private donations and cannot accommodate all the cats in need. The cats that cannot squeeze into this already taxed system often succumb to terrible illnesses and injuries on the streets.

Outdoor cats prey upon wildlife, putting Ontario’s amazingly diverse populations of wild creatures at risk, even in urban areas. Staggering statistics about wildlife deaths caused by cats aside, Ontario’s wildlife rehabilitators (the majority of who subsist solely or primarily on private donations) know too well the devastating effects of free-roaming cats first hand.

Like other wildlife rehabilitators, Toronto Wildlife Centre is inundated with hundreds, if not thousands, of calls every year about wild animals who have been injured or killed by cats. In the spring and summer months, baby animals in need of medical care who have been plucked from their nests or hiding areas by free-roaming cats are brought to TWC’s hospital in droves. Because each cat owner may only see their cat bring home a few animals, the scope of the problem can be difficult to appreciate.

For more information on cats and wildlife, see our
Frequently Asked Questions page, or check out our resource list.

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What Outdoor Cats Are Up Against

Some of the main dangers faced by outdoor cats are:

Predation by other animals
Although coyote attacks on cats tend to draw the most media attention, there are a number of wild species in Ontario that eat, or will fight with, small mammals such as cats. Birds of prey, for example, have been known to eat cats in residential yards even in highly urban areas.

Cats are frequently hit by cars, making this one of the most common type of injury veterinarians see in outdoor cats. However even veterinary records do not tell the full story, since many outdoor cats that are hit by cars do not survive long enough to get to a clinic for treatment.

Human cruelty
Staff and volunteers in animal rescue shelters can attest to the cruel and bewildering acts outdoor cats suffer at the hands of people.

Exposure to hazardous chemicals
Cats regularly encounter toxic substances outdoors, including pesticides and other poisons. Even regular “household” chemicals as in antifreeze – a chemical whose sweet taste is enticing to many animals – can seriously harm cats.

Exposure to debilitating diseases
Outdoor cats are exposed to devastating contagious diseases such as feline leukemia, feline immunodeficiency virus, feline distemper and rabies.

Outdoor cats easily pick up internal parasites (e.g., worms) and external parasites (e.g., fleas, ticks), leading to discomfort for the affected cat. Some of these parasites can be transmitted to other pets and people.

Outdoor cats often get lost or get picked up by other people (and in many cases dropped at overflowing animal shelters, where their prospects for adoption may be grim).

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The debate on whether cats should stay in or go out is often a heated one. Many pet owners feel that it is unfair or unkind to keep their cats indoors, and that this outweighs the potential risks for the cat and other animals.

Before making a final judgment on that, let’s weigh out two options. We asked domestic vets and wildlife experts what the pros and cons were for cats and wildlife when pet cats are allowed to roam freely. Here’s what they agreed on:


Looking at this comparison, it isn’t difficult to see that the benefits for cats and wildlife are far fewer than the risks. The only two benefits of allowing cats to roam outdoors can also be provided by indoor cat owners by giving their pets a proper diet and adequate stimulation. There is also the option,  for some pet owners, of building an outdoor cat enclosure if they still want their cat to enjoy the outdoors, but wish to keep them and wildlife safe.

One thing that isn’t on this list, however, are the costs and benefits for people of letting cats outdoors. Let’s face it -- letting your cat outside is much easier than keeping him or her in. If cats don’t receive enough stimulation, they’ll get bored and may whine at the door or cause damage to the house. Letting cats outside makes them a “lower-maintenance” pet, but as responsible pet owners we must consider the often devastating cost of this convenience to our feline friends…not to mention the other animals we share the planet with. And if that doesn’t sell you, say the vets, the veterinary bills might! Outdoor cat owners typically end up spending a lot more money in the clinics than owners of indoor cats do to treat the injuries, illnesses, and parasites that affect their wandering pets. Other benefits for people who keep pet cats inside? Peace of mind that your cat will be safer, a more bonded relationship with your pet, and the knowledge that you’ve saved the lives of many animals.

For more information, see our resources page.

  1. Based on an HSUS veterinarian study conducted in June 2001 by Jacobs, Jenner & Kent
  2. Canadian Federation of Humane Societies national animal shelter statistics, 2007
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How Can You Help

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A Word From the Vets

website Toronto Wildlife Centre American Bird Conservancy Toronto Cat Rescue Toronto Field Naturalists Habitat Haven Ontario SPCA Owl Foundation OWREN The Arboretum Earth Rangers Toronto Animal Services Off The Cuff Marketing CFHS The Ontario Trillium Foundation Project Chirp! AASAO Mississauga Harvey Cats Hotel
website Toronto Wildlife Centre American Bird Conservancy Toronto Cat Rescue Toronto Field Naturalists Habitat Haven Ontario SPCA Owl Foundation OWREN The Arboretum Earth Rangers Toronto Animal Services Off The Cuff Marketing CFHS The Ontario Trillium Foundation