We've had our two cats for over 6 years now--female and male. They are
both fixed. They have been getting along just fine until a week ago
when they suddenly started fighting.

Now, when they are in the same room, the male cat starts approaching
the female in an aggressive manner. The female cat starts hissing and
growling. If they start fighting, the female cat pees in her panic and
this iritates the male cat even more (he can't stand dirty litter
boxes and pee smell). We've kept them separated for a week now, but
things don't improve. Our vet is absolutely useless.

We tried Rescue Remedy in their water--not working. We used the trick
of giving them their favorite food when they are close. At the moment
they stop eating, they start fighting. We put one cat in a carrier and
let the other sniff it. Nothing. (When alone with us, the cats are
sweet and well mannered--they just can't stand each other.) We don't
know what to do... Do you have any ideas?
Gianna