unless you are mistaken or exaggerating and the cat is really eating,
drinking and urinating/defacating, then yes, get it to the vet.  Cats
cannot go without eating or drinking without serious health consequences.

I see... Perhaps you need to confine the more aggressive one to another
room. Or better yet... chastise the aggressive one in front of the
passive one. So she will see what happens to aggressors, and that there
will be a price to be paid for such future behavior. Then they will
both be in hiding and she will not feel so all alone! Another thing you
could do is to allow her special privileges. Let her sleep with you in
your closed bedroom, so she can relax without the constant fear of her
detractor's presence. Don't force her to come out. She will do so in
her own good time. It is quite obvious that she greatly fears the one
who considers her to be hiz territorial rival. She is not one, of
course. But the other does not know this, and will most likely continue
his pattern of tyranny that he has found to be so effective. At least
until he becomes used to this new abode himself, but of course by then,
it may be too late. The problem is, the fearful cat is so very much
afraid of the anger of the other that it will not even come out to eat
and drink. This is what I think. If this is actually the case, one
might try placing the good cat's food and water in a place where IT
feels safe. A place that is off-limits to the fear-inspiring other.
Despite all of the psychological prosing that one can get caught up in,
It is very important to be sure that she is not becoming dehydrated.
Take special care in gauging exactly how much water, food etc. that you
place as an offering vs. how much is left there in the morning. If your
cat is showing signs of dehydration, you should seek professional help
for her immediately. I'm not a professional or anything. It just seemz
like a common sense thing to do to me..

                                        IBen Getiner

I was just reading about feral cats (see the thread about Now Feeding
Outdoor Cats or something like that) and I'm wondering if the hider is
actually a feral cat. The site (www.neighborhoodcats.com) says that
truly feral cats will never be happy indoors and will spend their time
hiding. Someone posted something like that a few weeks ago, possibly
from the same site.

As I read the part about hiding, I thought of your post and wondered
if that's what is going on.

happyseducedg...@yahoo.com wrote:

I am sorry to frighten you so by the use of such a harsh world used in
such looseness. What I am driving at is... the cat sounds to me like
it's shutting down. But in all reality, it is not intentional and iz
probably just the fact that she is afraid to come forth and partake of
food or drink for fear of the other. You can see this in every aspect
of the animal kingdom. The passive ones will hide, and the aggressive
ones will prowl and dominate. I have actually seen instances (with
other species) where the aggressor will attact the passive one
relentlessly simply because the passive one tried to come out to eat. I
know your situation is not that dire, but I use it to make a point. I
hope this clears this up for you...
Also, on the subject of dehydration, when I was a lad, my family had
an outside cat that somehow got into poison. It disappeared for about a
week. We looked and looked, but it was nowhere to be found. Then we
found it under the shed all curled up in a niche. It growled at me,
even though it was technically 'my' cat and I knew it loved me. I
realized that it just wanted to be left alone. We told our vet and he
said that we just had to wait it out. That it might make it or it might
die. Finally, it came out. We rushed it to the vet, and that's where I
learned about the 'twist the skin' technique for checking for
dehydration. The vet showed us by doing this that the cat was indeed
very dehydrated. That skin practically stayed in the exact shape it was
in when the vet twisted it and then let go. He hydrated the cat and
kept it for a couple of days and everything was fine.
Forget the suicide thing. I did not mean that literally. Beware of
dehydration. I mean that literally and this is all I dare say on the
matter. Good luck....

                                                   IBen Getiner