It doesn't say that. In the Levitical Law, clean and unclean animals are described. Carnivores and bottom feeders, and those with a split hoof, are ceremonially unclean, so it would make sense that we will not see them in the afterlife. But in Revelation 19, we learn that Christ's return will be with Him riding on a horse, with an army of the angels and saved saints following after Him on horses. Horses (and animals without a split hoof) are among the clean animals.