Outside cats live for a much shorter time than indoor cats simply because they are exposed to different dangers they would never have been exposed to by remaining indoors. However, that is mostly meant for free roaming cats, not ones we let out occasionally under a controlled environment. But even then, we would have to deal with fleas, ticks or maybe other parasites just to let our cats out for a little while in the backyard. We don't want to see our cats cooped up, bored and depressed. So here are some ways in which we can let them have some freedom while drastically reducing the chances of an accident or parasites getting on them.
In the event that your cat might escape, no matter how careful you are with outside enclosures, make sure they have a collar with their information on it. That way if someone finds them, they can call you and your pet will be returned. Some people like chip implants so the cat doesn't have to wear a collar (which some of them hate wearing). It's a good idea and it's easy for the vet or shelter to scan and identify them so they can notify you where your cat is being held.
Vaccinations are important, as they not only protect your cat, but other cats and humans as well. Certain vets or even stores have clinics for vaccinations that are cheaper than usual. The Vetco website can show you where there are clinics in certain states, or you can look up your local locations or pet stores for them.
You should also spay or neuter your cat so they don't get pregnant or create more outside cats in the process. It might still be a good idea if you're keeping them indoors, unless you really want kittens, because they will probably find a way out anyway. And plus, it helps to stop males from spraying, at least most of the time.
Building A Fence
If you have a nicely sized yard, a fence could be a good option, as it gives your kitty a lot of room to play in and they can be free to run and really enjoy themselves. It can be expensive though, unless you already have one, and they need to be erected high enough so the cats can't jump out and escape. As a general rule, cats can jump 5 times their body height, so we're talking about 5 feet high, more or less.
You also don't want the fence to be made of a material that the cat can claw their way out of. Their claws can latch onto just about anything, so a wooden fence might be the better option, versus a chain link fence. Make sure they can't find a vulnerable area to squeeze through either. If you're concerned about parasites, you can give your cat a flea/tick medication ahead of time, and also check them once a week or so. You don't want them on your pet, nor on yourself or in the house either.
You can buy a huge cage to put your cats in so they can enjoy the outdoors and get some fresh air without them stepping onto the grass. This way there is less chance for them to attract parasites or escape the yard. The shelves can be adjusted to change things up and some have a mini hammock for the cat/s to lay on.
They also have some fancy net enclosures that allow your cat to walk around, surrounded in a net/mesh material. However, the bottom might not protect the cats from parasites, though it does allow them to smell the grass and eat it if it comes up through the mesh. They also have hammocks your cats can sleep on just like the cages. These can be more expensive than cages, but allow more freedom for your cat and little canopies that provide shade for them.
If you don't mind that your cat goes wondering close by, you can install a flap on the bottom of the door for the cat to go in and out as it desires. You can let them leave to go outside or onto a screened porch just to get some fresh air. A possible downside to this is that another animal could get in if it leads out to the yard directly.
You can walk your cat just like you would walk a baby, in a stroller. This stroller is enclosed, of course, and gives your cat some fresh air and sights while staying safe. You both get outside time together while they remain shielded from the sun and parasites.
You might even be able to train your cat to walk with you on a leash, but good luck with that, as most cats will put up a really good fight, especially indoor cats that don't go outside a lot. It would be easier if you start this when they are a kitten so they get used to it. They might try to get out of a basic collar, but you can also buy a harness that fits onto their body so they can't escape.
Carriers are a lot like strollers, just without the wheels and you have to carry your cat around. They are especially good for taking your pet to the vet so they can see what's happening around them, although that may not be a good thing necessarily. But in terms of just getting outside, you can carry your cat to the park or backyard and sit there with them.
All of these things could also work for small dogs, and they do have the same kind of products. This article focuses more on cats though, because they can be more fussy and get stressed more easily outside than dogs, if they are not used to it. So with this information, you can decide what is best for you and your cat, depending on the situation. Good luck!