Indoor vs Outdoor Cats: Life Expectancy, Risks & Compromise

In short:

An indoor cat enjoys a longer lifespan and is exposed to a fraction of injuries, infections and accidents compared to an outdoor cat.
An outdoor cat gets more exercise and natural stimuli, yet pays for it with traffic dangers, predation, diseases and poisoning.
The indoor/outdoor cat – the one with partial outdoor access – becomes the modern veterinarians' golden mean.
Indoor lifestyle works effectively only with proper enrichment: playtime, climbing, windows, scratch posts and clean litter tray.
If you decide to let your cat out, microchip it, vaccinate it and bring it in at night.

The question "Should I let my cat outside?" is one of the most heated ones in the feline pet community. According to the recommendations issued in the U.S., an indoor or partially indoor lifestyle is strongly preferred by the vast majority of vets. In the U.K. and the majority of Europe, most of the cats enjoy freedom. The point is that both groups love their pets. Here is the information backed up by science to help you make the choice on behalf of your cat.

Outside Cats

Outside cats are those with free access to the outside world. These cats suffer from the following hazards:

Traffic. For an outside cat, this risk factor is one of the major ones. An automobile accident is one of the main reasons of injury and death for any outdoor cat.
Infectious diseases. Feline leukemia (FeLV) and FIV pass easily from cat to cat; parasites are a much more frequent problem for outdoor cats.
Fights and abscesses. Territorial conflicts with other outside cats often result in bites that lead to abscess formation.
Predators. Coyotes, birds of prey and dogs hunt cats, especially in the suburbia.
Poisoning. Antifreeze, rodenticides, slug and snail baits and garden products are hazardous for the health of outside cats. An outdoor cat cannot tell you what it has consumed.
Being lost or trapped in someone's garage or basement.
Acts of cruelty from humans. It happens all too often.

Besides, the real lifespan of an outside cat is hard to measure, because many cats that disappear are never found and the cause stays unknown. However, the biggest problem of an outdoor cat is the impact it makes on wildlife. The estimates obtained in the well-known article by Loss et al. (Nature Communications, 2013) show that free-roaming cats in the USA kill 1.3 to 4 billions of birds and 6.3 to 22.3 billions of mammals per year. Most of them are killed by un-owned cats; however, owned cats contribute too.

Indoor Outdoor Cat

The indoor/outdoor cat lies between the two extremes. Here is a comparison table for these three categories of cats.

Life expectancy

Indoor cat: Often 12-18+ years
Indoor/outdoor cat: Depends on the time spent outside
Outdoor cat: Shorter

Injury risk

Indoor cat: Low
Indoor/outdoor cat: Moderate
Outdoor cat: High

Infectious disease risk

Indoor cat: Low
Indoor/outdoor cat: Moderate
Outdoor cat: High

Exercise and stimulation

Indoor cat: Limited
Indoor/outdoor cat: Moderate
Outdoor cat: High

Behavior problems related to boredom

Indoor cat: Unlikely, if enriched
Indoor/outdoor cat: Mostly unlikely
Outdoor cat: Mostly unlikely

Impact on wildlife

Indoor cat: Zero
Indoor/outdoor cat: Minimal
Outdoor cat: Significant

Owner effort

Indoor cat: Regular enrichment, litter trays, playtime
Indoor/outdoor cat: Vaccines, parasite control, supervision
Outdoor cat: Regular worry

Comment: you often hear statements like "indoor cats live 15 years, outdoor cats 2 to 5". The second number is very popular; however, it is not supported by reliable data. The only thing that can be definitely said is that having an outdoor access increases the risk of injuries, infectious diseases and accidents. As a result, the gap in indoor vs outdoor cats lifespan exists; nevertheless, the actual number remains unknown. Indoor cat lifespan depends on the weight, dental health and kidney disease; hence, an indoor cat requires care too.

Owners of indoor and outdoor cat households (having some cats of each category) claim that they see a difference in vet bills. In a household with an indoor and outdoor cat, the cat that goes out tends to return home injured, infested with parasites or with abscess.

Should I let my cat outside?

The answer is up to you, but these questions will help you make it. Should I let my cat outside if...

You live near a busy road? The risk of traffic accidents is very high. No, the majority of veterinarians will say.
You live in coyote country? The Western U.S. suburbs lose many cats because of coyotes. At least keep your cat indoors from dusk till dawn.
Your cat is accustomed to outdoor life and miserable in the house? A slow adaptation process, catio or leash walks may help.
Your cat is young, healthy, vaccinated and microchipped, and you live in a quiet place? The risk is smaller, yet not equal to zero.

There is some real-life experience of the owners that confirms these statements. People who switched an outside cat to indoor lifestyle claim that the first two weeks were tough for the cat (yowling, scratching the window frames), while in a month the cat adjusted to its new life. Other cat owners, especially in rural areas, say that their cats never adapted. There is no single solution, yet there is a safer default choice.

In case you've decided to let your cat outdoors, establish some rules: only during daylight, before dusk, microchipped, vaccinated and spayed/neutered, using flea and worm prevention regularly.

How to Have an Outdoor Cat

If you want your cat to have an outdoor experience, here are some tips on how to have an outdoor cat safely:

Pros

More exercise and natural hunting.
Fewer boredom-related problems.
Fresh air, scents, variety.

Cons

Greater risk of injury, disease and death.
Wildlife losses.
Worry, neighbor conflicts and more frequent vet visits.

Practical steps:

Catio. An enclosed patio or window box allows an outdoor air to your cat without risks. This solution is the best of both worlds for most people.
Leash. Many cats can be trained to walk on a harness. Start indoors, keep the training session short, and never tie a cat to something outside.
Supervised gardening. Walk your cat in the garden.
Cat-proof fence. A special angled fence will keep your cat in the yard.
Timetable. Out during the day and back in before dusk, when predators and traffic are most active.

And if you've decided to turn an indoor cat into an outdoor one, here are some tips on how to make an indoor cat an outdoor cat safely. Do it gradually. Begin with leash walks, and then provide a supervised outdoor access to the enclosed garden. Never just open the door for your lifelong indoor cat. People who look for tips on how to make an indoor cat an outdoor cat underestimate how disoriented a lifelong indoor cat can be outside – it does not know the territory, escape options and local cats.

My Indoor Outdoor Cat Hasn't Come Home

This is every owner's worst nightmare. My indoor outdoor cat hasn't come home, and it has been hours already. What should you do now?

First, check places around your house. Most lost cats are discovered nearby.
Second, search at night with a flashlight. Cats hide during daytime and their eyes are visible in darkness.
Third, call their names quietly and shake the treat bag. A scared cat will not make noise.
Fourth, file a report in nearby shelters and vet clinics.
Fifth, post a photo in your Nextdoor and Facebook neighborhood group.

In case you are looking for the tips on how to find a lost indoor outdoor cat, remember that a cat that has been accustomed to outside life may roam farther than an indoor cat; however, many cats are discovered within a few streets from home. In case my indoor outdoor cat is missing for a few days, increase the area of the search and make flyers. An indoor outdoor cat missing for several days may still return home. Many cats do return even after weeks.

Moving Indoor Outdoor Cats to a New Home

Moving an indoor outdoor cat to a new home involves a specific risk: cats may try to return back to their familiar territory. According to the recommendations of international cat organizations (such as International Cat Care) it is better to keep cats indoors for a few weeks after the move in order to adapt them to a new place.

Verdict: in case you are moving your indoor/outdoor cat to a new place, keep it inside for at least 2-4 weeks, provide a quiet room and let the cat outdoors before a mealtime.

The same is true for moving indoor outdoor cats to a new home in another city. For more information see our guide on moving cross-country with cats.

Indoor Cats Require More Than a Litter Box

In case you chose indoor life for your cat – either full-time or partial – it totally depends on you to provide everything that the outside world used to provide previously. Exercise, hunting, exploring and toilet place are the things that an outdoor cat had on its own. The last item is often overlooked. An outdoor cat may choose its toilet place; an indoor cat always has to use a litter box. Hence, clean and odourless litter tray is essential.

Paco & Pepper olive pit litter does not produce any dust, creates dense clumps and controls the smell without using additional fragrances – this is particularly important in case you live in a small apartment where the litter tray is always nearby. More information on the litter boxes is available in our articles on how long a cat can go without a litter box and whether a feral cat will use a litter box.

FAQ

Is it true that indoor outdoor cats are happier? Yes, indoor outdoor cats may be happy. Also, indoor cats that live in an interesting environment may feel good too. Happiness of a cat depends much more on enrichment and routines rather than on doors.

Is it cruel to keep an outdoor cat inside? No, it is not if the transition is gradual and the cat has climbing and playing opportunities.

Do outdoor cats require different vaccination schedule? Usually yes. They are vaccinated against feline leukemia in addition to regular vaccines. Consult your veterinarian.

What should I do if my indoor outdoor cat hasn't returned after 2-3 days? Continue the search and change the tactics: put up flyers in a few blocks away, ask neighbors to check their sheds and garages, personally visit your local shelters. Descriptions of your cat over the phone do not help much. Leave a worn piece of your clothing near the door. Cats often return home after weeks.

What about indoor vs outdoor cats in cities? Urban cats suffer from higher risks of traffic; therefore, vets advise indoor lifestyle or at least catio in cities.

Whichever choice you make, make it wisely.

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