Your cat is likely to live longer if you don’t let them roam – new study
- Written by Mike Calver, Associate Professor in Biological Sciences, Murdoch University
Warning: some readers might find images in this article distressing.
We all know cats represent a major threat to native animals and birds. Australia’s 5.3 million domestic cats kill a total of 546 million animals each year in Australia. What’s less well known is allowing your domestic cat to roam outside exposes them to considerable danger – and the risk of a short life.
About two-thirds of all Australian cat owners have had a cat die while out roaming. The top risks are road traffic accidents, fighting and falls.
Our recent research review found keeping your cat at home at all times isn’t just good for wildlife – it’s much safer for your cat.
Losing a cat is tragic. But there are other risks too. Many owners rack up large veterinary bills while their cats are left with lifelong health conditions. Our review also found this situation is not unique to Australia, but reflects the global risk faced by free-roaming cats.
What are the risks?
Cameras mounted on collars provide a cat’s-eye view of the hazards roaming cats face. In one study of 55 free-roaming felines in the United States, 25% risked poisoning by eating or drinking while away from home – any substance could be hazardous. Nearly half (45%) crossed roads, 25% encountered other cats, 20% crawled under houses and 20% explored storm drains.
This isn’t just American feline bravado. When cameras were fitted to 37 cats in New Zealand, 59% drank away from home, 40% ate away from home, 32% crossed roads and 21% risked falling by climbing onto roofs.
Australian cats are no exception. In one study, 428 radio-tracked cats averaged 4.8 road crossings per day.
What are the outcomes?
If you’re a fan of The Simpsons you might recall the fate of their family cats: Snowball I and Snowball II died on the road, Snowball III drowned, Coltrane (AKA Snowball IV) fell to his death, and Snowball V is still with us. The reality is uncomfortably similar. Our review found that trauma – mainly road traffic accidents, fighting and falls – kills or injures many free-roaming cats globally.
In a recent UK study, road traffic accidents were the leading cause of death for cats aged less than one year old all the way to eight-year-old cats.
This aligns with European estimates, which suggest 18–24% of cats are struck by a car during their lifetime, with around 70% of those incidents proving fatal. Victims are often under five years old and predominantly male. Risks are higher for those not desexed, as they tend to roam wider and more frequently.
Love and status offer no protection. Former New Zealand Prime Minister Jacinda Ardern’s cat, Paddles, colloquially known as New Zealand’s first cat, died after being hit by a car in 2017.
The dangers extend well beyond road accidents. Roaming pet cats face serious infectious diseases, such as Feline Immunodeficiency Virus (FIV), and frequently engage in fights, often developing abscesses that can kill and require expensive veterinary treatment.
While it’s hard to quantify the instances of deliberate human cruelty to cats, there is global evidence for deliberate poisoning and injury to roaming cats, many of which die before receiving medical intervention.
In one study tracking 55 roaming cats in Western Australia over just eight months, two were poisoned, one lost a front leg in a traffic accident, one fractured two canine teeth in a fall, and two required veterinary treatment for fight-related injuries.
Drawing all these factors together, we estimated outdoor pet cats have lives at least 2–3 years shorter than the population of contained pet cats. Those that survive accidents or disease may have lifelong disabilities.
Tugay Aydin/Pexels, CC BY
How can you reduce the risks?
The simplest way to protect your cats is to contain them on your property, just as Australians do with other domestic animals. Extensive advice is available on how to keep cats happy and healthy while contained.
Importantly, containment doesn’t mean keeping your cat indoors at all times. Backyards can be modified with fence-top rollers to prevent escape. Some owners enclose part of the yard to create a “catio” – an outdoor cat enclosure – allowing their cats to enjoy fresh air and sunshine while remaining secure.
Many cats can also be trained to walk on a harness or leash, making it possible to take them for supervised outings. A recent report from Norway found providing controlled outdoor access is often important for maintaining cat wellbeing.
Cats need to be entertained when in the house. They enjoy outside views, toys, scratching surfaces, above-ground climbing and sitting spaces, and opportunities for play. They are naturally solitary animals, so places to hide are useful.
If cats can’t go outside to toilet, they will need two indoor litter trays. Because cats are fastidious, trays must be cleaned frequently. In multi-cat households, provide one litter tray per cat, plus an extra. Place the trays in separate, quiet locations, and never beside the food bowl.
Responsible cat ownership
Australians love their cats. In 2019, roughly a quarter of Australian households owned a cat. By 2025, that figure had risen to a third. Over the same period, households reporting they kept their cats indoors rose from 36% to 48%.
Perhaps we are finally valuing our cats as we do our dogs and listening to Aussie songwriter and singer Eric Bogle’s sage advice:
Oh you who love your pussy be sure to keep him in. Don’t let him argue with a truck, the truck is bound to win. And upon the busy road don’t let him play or frolic. If you do I’m warning you it could be CAT-astrophic.
Authors: Mike Calver, Associate Professor in Biological Sciences, Murdoch University 
