I am wondering if cats can get stomach viruses.  I ask because we adopted a
new cat and he had diarrhea for a bit after he first came home (vet checked
him out, tested for parasites, etc., and he was ok otherwise).  She surmised
it could be stress from the new environment.  Then our kitten got it for a
few days.  After a vet visit, including a fecal float (negative), he was
prescribed an antibiotic and a special food.  He's getting over it.  Now our
10 year old female cat has it, along with one vomiting incident (not a
hairball).  There are no poisons or anything out that they could have all
three gotten into (at staggered times, no less?).

Can cats get stomach viruses?  I will take my female to the vet Monday
depending upon what y'all say.  She seems better today.  We wondered if the
special food, Prescription Diet I/R, could have caused her upset.  She's
used to regular Science Diet adult.

They are all eating, drinking and playing normally.

Also, our adopted cat has what seems to be a cold.  He had conjuctivitus,
which he is still getting eye drops for (vet prescribed), but he sneezes
occasionally and his eyes are still watering.  Neither of the other cats has
shown any symptoms, and they've all been together for over a month now.
Could it be a combo of the conjuctivitus (other cats don't have this,
either) and allergies?  Or just the conjuctivitus?

All three cats are up to date on shots and tested negative for all things
they were supposed to : ).

Thanks for any help!