Well, we know horses are extinct in William Gibson’s Sprawl universe (Neuromancer and its sequels and related short stories).
"Hey, Christ,” the Finn said, taking Case’s arm, “looka that.” He pointed. “It’s a horse, man. You ever see a horse?”
Case glanced at the embalmed animal and shook his head. It was displayed on a sort of pedestal, near the entrance to a place that sold birds and monkeys. The thing’s legs had been worn black and hairless by decades of passing hands. “Saw one in Maryland once,” the Finn said, “and that was a good three years after the pandemic. There’s Arabs still trying to code ’em up from the DNA, but they always croak.”
