March 26, 2026, 8:19 am | Read time: 6 minutes
Many cat owners believe that only outdoor access leads to a happier life for their cat. However, a comprehensive scientific analysis paints a different picture: Cats that regularly roam outside face a significantly higher risk of injuries, diseases, and premature death, while indoor cats tend to live longer. An overview study compiles numerous research findings—and concludes that “confinement” often harms cats less. PETBOOK editor Louisa Stoeffler summarizes the key insights.
What Are the Real Effects of Outdoor Access?
House cats are among the most popular pets worldwide and live on every continent except Antarctica. However, with their increasing spread, the discussion about their impact on wildlife and potential risks to humans and livestock from diseases has also grown.
Many debates focus on cats hunting birds and other wildlife. These discussions are often controversial. Some scientists consider the impact significant, while others see it as overestimated and point to other factors such as habitat loss or urbanization.
The authors of the current study argue that these conflicts often obscure another important issue: the welfare of the cats themselves. Veterinary organizations have been pointing out for years that free-roaming cats are exposed to significantly higher risks. These include traffic accidents, fights with other animals, infectious diseases, poisonings, and even intentional abuse by humans. It has long been estimated that indoor cats live longer than those with outdoor access.
At the same time, exclusive indoor living can also cause problems, such as a lack of exercise, obesity, or behavioral disorders. Therefore, the central question arises: Do the advantages or disadvantages of keeping cats without unsecured outdoor access outweigh each other?
Main Dangers of Outdoor Access
The study was conducted by Michael C. Calver and colleagues from Murdoch University in Australia and other international research institutions. It was published in 2026 in the journal “Global Ecology and Conservation.”
The authors analyze in an extensive review of 2,495 publications the health and welfare-related consequences of different housing forms for house cats (Felis catus). The focus was on four main dangers for cats:
- traumatic injuries, such as those from traffic accidents, falls, or animal fights
- infectious diseases and parasites transmitted during encounters with other cats or wildlife
- poisonings, for example, from bait, rodenticides (rat poisons), or toxic plants
- abuse or neglect by humans
Additionally, the authors compared studies on cats with outdoor access and those in controlled environments. They considered data from veterinary practices, insurance statistics, owner surveys, and studies with cameras on cat collars. The aim was also to examine whether arguments from animal welfare—rather than just conservation—could more strongly advocate for controlled cat housing. This includes secured outdoor access on balconies or private properties.
Injuries and Traffic Accidents Most Common Emergencies
The evaluation shows a clear pattern: Cats with unsecured outdoor access are significantly more exposed to health risks than cats kept mostly or entirely on their own property. Consequently, injuries are among the most common emergencies for cats worldwide. Traffic accidents, falls from heights, and fights with other animals are particularly frequent. In many studies, most injured cats are younger than five years, and male cats are disproportionately affected.
Another major risk is infectious diseases. Cats with outdoor access come into contact with other cats more often and therefore have higher infection rates for diseases like the feline leukemia virus (FeLV) or the feline immunodeficiency virus (FIV). For example, a U.S. study found FeLV exposure in indoor-only cats at 4.45 percent, but up to 14.15 percent in cats with outdoor access.
Poisonings also occur more frequently in free-roaming cats. A study from Scandinavia found that 59 poisoned cats had been unsupervised outdoors the day before. Video footage from cats with collar cameras also shows how often risky situations occur: In one study, 45 percent of observed cats crossed roads, 25 percent encountered unfamiliar cats, and about a quarter drank or ate potentially dangerous things outside.
Cats Live Up to Three Years Longer Indoors
These risks also affect lifespan. According to the analyzed data, indoor cats live on average about two to three years longer than cats with outdoor access. Overall, the average lifespan of free-roaming cats is only about 70 to 80 percent of that of indoor cats.
The findings suggest that keeping cats without free access to the environment can have significant health benefits. This is particularly relevant for veterinarians, animal welfare organizations, and conservation experts advising cat owners. In the long term, this insight primarily serves animal welfare. The authors emphasize that these arguments can often be more convincing than purely conservation concerns when deciding whether to let a cat roam unsupervised. Many cat owners react defensively to suggestions that their pets kill wildlife—or downplay the ecological consequences.
However, warnings about risks to their own cat—such as traffic accidents or serious illnesses—often meet with more understanding. At the same time, the authors stress that indoor living is only optimal if cats are sufficiently engaged. This includes play opportunities, climbing options, retreats, or secured outdoor areas like so-called “catios.” Such measures can prevent a lack of exercise and behavioral problems.
“Golden Rules” for Indoor Living
To keep cats engaged indoors, PETBOOK recommends varied activities. These include:
- Window seats with a view
- Toys and scratching surfaces
- Elevated climbing and seating areas
- Retreats for hiding
- Secured areas on the balcony or in an escape-proof garden (catios)
If cats live exclusively indoors, they also need enough litter boxes. The rule of thumb is: number of cats plus one extra box. A single cat should have two boxes available, a pair three. They should be placed in quiet locations and cleaned regularly—and never near the food bowl.
Also, walks with a harness and leash are possible. A study from Norway shows that controlled outdoor access under supervision can promote cats’ well-being. However, animal welfare is also decisive here. If a cat does not feel comfortable on a leash, it does not benefit from it.
Outdoor Cat or Indoor Cat: What’s Better for the Pet?
Often Underestimated: These Dangers Lurk for Cats in the Garden
Less Hunting of Roaming Cats
According to the study, controlled housing benefits not only the cats themselves but also wildlife, as less hunting occurs. The study compiles a large amount of existing research, providing a broad overview of the risks and benefits of different housing forms.
At the same time, this approach also has limitations. The analyzed studies vary greatly in their methods, datasets, and geographic regions. This makes it difficult to compare the results exactly or to statistically combine them. While in Australia, for example, unsecured outdoor access is almost nonexistent, it is still common in Germany or even required by animal shelters.
Clear Message for Cat Owners
Another issue is the so-called data distortion from veterinary statistics. Many studies are based on cases from veterinary clinics. Cats that die immediately in an accident or disappear while roaming often do not appear in such data. As a result, the actual risks to free-roaming cats could even be underestimated.
Despite these limitations, the authors conclude after evaluating numerous studies that the benefits of controlled housing clearly outweigh the disadvantages. For cat owners, this results in a clear message: A safe environment on their own property or indoors—combined with sufficient engagement and environmental enrichment—can improve well-being and ensure that cats live longer overall. 1