How would the world be different if human lifespans remained the same, but cats lived for a thousand years?

Cats would become official heirlooms, passed down between house and family.

You know how there's all those fuckin people who swear they were Napoleon or Cleopatra in a previous life? Something like that.

"I'll have you know that Mr Mittens was a favorite bed cat of Charlemagne!"

Cats would not evolve very quickly. Because of their ancestors filling the ecological niche, taking resources, new generations wouldn't have room to compete. So we would have less varieties of cats.

If they still bred the same way, the world suffer mass extinction.

Cats would be studied and experimented to create all sort of grift like snail juice creams and the entire culture of Chinese animal "medicine" we have today.

Maybe what we have now is actually better for the cats.

Remember, Mittens used to run the Holy Roman Empire, so a little bow and groveling go a long way…also he puked on the rug.

News: "Audrey Hepburn's cat sold for $1000000 at auction"

Is the lifespan of cats in this scenario 1,000 years or 9 x 1,000 years because of their nine lives?

Their hearts would have to beat a lot slower, as pretty much every species gets 1-2 billion heartbeats per lifespan.

Cats would put you down when it was time for you to go home from old age

how long then would mice be supposed to live? (squeaky noise, here)

Well I don't know about the world but I'd still have my cat.

Cat worship would go up. Also their behavior might be worse from being spoiled all the time.

There may be a possibility of increasing their danger levels since they will have way more hunter experience.

I’d still prefer dogs.