All it takes is one exposure, and your "indoor" cat can infect your remaining pets (and you).

This entire topic is is marred with silly nonsense like "your only risk is mishandling cat feces", which totally ignores things like:

1) The cat litter box is covered in microscopic parasite-containing cat feces

2) The cat tracks feces-covered litter out of the box into the living space, which further spreads the parasite. If you walk barefoot through your house, you will step on cat liter pieces eventually which are again covered in microscopic feces.

3) The cat steps in litter covered in cat feces from other cats, gets it on its paws, which it then licks, starting the infection cycle over again. Multiple cats can easily keep a perpetual infection cycle going.

4) Cats, even well trained ones, routinely climb on top of furniture/eating/cooking surface and coat them in their feces. My parents were shocked after installing an interior camera when they saw their "well-behaved cats that never do that" walk all over their dinner table, kitchen counters, open and go inside cabinets etc etc. They are smart enough to know when you are around or not, and to not act like this when you can see them.

5) Cats have sharp claws, and even well behaved ones can accidentally scratch you or scratch a toddler that gets too close etc. This will then directly introduce cat feces to your blood stream.

Once exposed, the initial symptoms are mild flu-like symptoms and not a huge deal (unless you are pregnant, in which you will likely experience a miscarriage. Pregnant women should not be exposed to cats, or be in a household that has indoor cats). The real issue is the long term cysts they leave behind in your brain, causing a latent inflammation and immune response that seemingly interacts with your dopamine system in poorly understood ways. For example, latent cyst-stage toxoplasmosis significantly increases your risk of developing schizophrenia.

How can an indoor cat ever clean themselves though? It doesn’t seem like most indoor cat owners bathe the cats, do they?

Bathing cats can give them infections if the water gets in their ears. Generally, they clean themselves in a freshly cleaned litter box, what's called a "sand bath" by rolling around. They also clean themselves by licking themselves. They do a very good job, I've been around cats my whole life and none of them smell except perchance the fat ones that cannot lick their butts and sometimes have a bit of a dirty butt.

I'm not sure if you asked the question in regard to disease -- but even indoor cat poop will not carry diseases. Perhaps E. coli or other bacteria already in the cat's gut (and our guts too), but toxoplasmosis is not going to pop up unless it's in the cat food (uncooked pork, etc.) or the cat already has it. It is another common mythology that somehow poop has "disease" in it. It has no more disease than we already possess...

>what's called a "sand bath" by rolling around.

I'm sorry, but is this a joke and I'm just missing it? I find it hard to believe that you are seriously suggesting a cat rolling around in a feces-covered litter box is "cleaning itself".

>freshly cleaned litter box

There is essentially no such thing as this. You would need to completely remove the litter and sanitize the box with bleach _each time your cat poops_. No one does this, they scoop out poop and put the contaminated scoop in a bucket or something. The next time the cat enters the "clean" box it is covered in it's own feces, and your scoop acts as a cross-media reinfection device. Litter boxes are, in practice, perpetually dirty things.

Cats lick themselves to get clean. They don't bathe even when they're outside.

Cats are not "clean" after they lick themselves, if anything this behavior is primarily responsible for the cultivation of a parasite lifecycle that has co-evolved to the cat's gut.

Cats, especially ones who share litter boxes, routinely get covered in potentially parasite-bearing feces via litter boxes and ingest it via grooming. This allows for easy additional spread/cross infection.

"Cats lick themselves, therefore they are clean" is a long-discredited but persistent myth.

The question was not "are cats clean," but "how do indoor cats clean themselves?"

Indoor cats clean themselves in the same way as outdoor cats, by licking themselves.