Are horses the only animals which cannot be physically sick?
I assume by ‘physically sick’ you are referring to vomiting, since all animals can get sick as in become ill. Horses are not alone in their inability to vomit – they share this trait with the other members of the family Equidae, such as donkeys and zebras. Many rodents, including rats and mice, cannot vomit, and neither can lagomorphs such as rabbits and hares.
