Can stress make my cat throw up?

Yes. The gut and nervous system are tightly coupled in cats, and stressors like a new home, a new pet, a schedule change or a recent vet visit can produce mild GI upset that includes vomiting. The clue is timing: did the vomiting start right after a change? Most stress-related vomiting clears on its own within a few days as the cat adjusts. Helping along: keep her routine predictable, give her hiding spots and elevated perches, and reduce competition at the food bowl in multi-cat homes.

When to call a vet: if vomiting lasts more than a few days, or her appetite drops, treat it as more than stress and see your vet.