I do find pets amusing. If you have a dog, all of the concerns most people voice about shoes applies to the dog. And they often seem to seek out poop to step in. We've been forced to bath our dog because he found coyote scat and thought that was good to wear.

All the while they ignore the litter box... And flush their human toilets with the lid open...

The world's a gross place. I know it's unavoidable for some (e.g. OCD) but by and large, I tend to think people spend an inordinate amount of time pursuing an unreasonable level of cleanliness.

Anecdotally, this checks. Shoes off, dog sits on the couch, dog’s habits fall under the field of bacteriology.

It's like fuzz testing for your immune system.

As a child I had to wash our dog's paws in winter/wet weather and a quick wipe otherwise. Dirt is dirt, nobody wants to walk on dirt at home.