By Dr. Becker
Cats who live outdoors tend to live much shorter lives than indoor cats. Compared to indoor cats, outdoor cats face an increased risk of injury, poisoning and human abuse and theft, and are more likely to be exposed to predatory wildlife, infectious agents or extreme temperatures.
However, it must be acknowledged that cats, though considered to be animals that can safely and humanely be kept indoors, are only “semi-domesticated” and actually have maintained many of their wild instincts, despite living with humans for nearly 10,000 years.
In a new position statement released by the American Association of Feline Practitioners (AAFP), it’s noted that there are both benefits and risks to keeping cats indoors, although environmental enrichment can help to reduce these risks, including behavioral problems that may occur among cats kept indoors in a non-stimulating environment.1 According to AAFP:
“Consideration for longevity often underlies the decision to keep cats indoors. However, a lifestyle choice made with the sole intention of increasing longevity — but in an impoverished or inadequate environment for each cat in the household — is not in the cat’s best interest.”
What Are the Risks of Keeping Cats Indoors?
The AAFP position statement suggests an indoor/outdoor living arrangement, in a safe environment, is best for cats.
This does not mean allowing your cat to roam freely outdoors, however, which puts her at significant risk of getting hit by a car, preyed upon by wildlife or even stolen. Instead, safe indoor/outdoor living, which I’ll explain below, is recommended.
Cats can be kept indoors only, but for optimal mental health cats need simulation of hunting and foraging, playtime and access to vertical space.
Without this, the AAFP noted multiple risks that could occur, including increased incidence of behavior problems or the inability to express normal cat behaviors like scratching or urine marking. If the latter behaviors are done indoors, it puts them at risk of being given up to a shelter or even euthanized. Other risks include:2
✓ Inability to express normal cat behaviors
✓ Increased incidence of behavior problems due to reduced access to resources
✓ Increased incidence of behavior problems due to the cat’s social needs not being met
✓ Inability to choose to live solitarily or with other cats they like
✓ Inter-cat conflict and related behavior problems
✓ Lack of stimulation
✓ Lack of hunting and normal feeding behavior
✓ Lack of exercise
✓ Obesity and associated health risks like diabetes
✓ Stress-associated disease, including feline idiopathic cystitis and gastrointestinal disease
✓ Physical, social and emotional needs may not be met
How to Safely Provide an Outdoor Experience for Your Cat
Providing your cat the opportunity to experience the outdoors safely while also living indoors provides the stimulation your cat needs mentally without the risks of free roaming. It also gives your cat an opportunity for beneficial grounding.
One option is to walk your cat using a cat harness and leash. Most cats, especially kittens, can be trained to walk on a leash, but not every cat will enjoy the experience. You’ll know best whether your cat has the personality to enjoy taking a walk around the neighborhood or whether it would simply stress her out.
Another alternative is to create a safe outdoor enclosure or cat patio — catio — which allows feline family members secure access to the outdoors. The enclosure should be open air, allowing your cat to feel fresh air and sunlight, but shielded enough to prevent escape or a predator from gaining access.
Elements of a Perfect Catio
Ideally, allow your cat free access to the catio via a pet door or tunnel. Walkways installed at different heights add interest, as do various platforms, hammocks, ramps, shelves and cat trees. Make sure the catio provides spaces for your cats to scratch (including at least one scratching pole for each cat).
You’ll want to be sure to give your cat vertical space to explore, which can be achieved by using platforms as “steps,” allowing your cat to gain access to high-up lounging spots. Add in a few hiding spots, especially if you have more than one cat or a timid cat, and make sure part of it is shaded.
Some cat owners like to add catnip and other cat-friendly herbs to the catio for cats to nibble, which provides a foraging experience. As for size, you can get as elaborate as you want, but DVM 360 suggested this as a guide:3
“The optimum size of a catio will depend on the number of cats and how well they all get along with each other.
For cats that also have free access to indoors, aim for at least  square meters of floor space for each cat, with a minimum height of  meters (around 6.5 feet), and then create vertical space and hiding locations to increase the available space further more.”
You can also add a water bowl and litterbox to the catio, especially if you find your pet likes to spend a lot of time there. However, even if your catio is secure, I don't recommend leaving your cat in an outdoor enclosure if you're not home.
When you are home, give your cat free reign of the catio (assuming the temperature isn’t extreme). By providing this outlet to the outdoors to your cat, you’re helping her to express her natural cat instincts while providing the valuable mental and emotional stimulation that she needs to thrive.