Siamese kittens & cats in Richfield, Utah

Cleo is about 7 years old. She is a Tortoise Shell Siamese cat. We have had her since shortly after her birth. We also have her brother, who is an orange tabby. Most of the time they get along perfectly but every once in a while a cat from the neighborhood comes into our yard. If either of our cats see this neighbor cat, they turn into homicidle maniacs. It takes anywhere from 1 week to 1 month before these gwo can get along again. They are bonded, litter mates and I am heartbroken that we have to rehome her. She is, as most Siamese cats are, more stand offish and the other cat has bonded with my husband so unfortunately she is the one that we have to rehome. While she is in this mood, we have to keep them completely separated. We have taken her to the vet and there is nothing medically wrong with her. We cannot figure out why the sight of this one cat does this but it does. Any other cats or animals come on to our deck it all but ignored. She is an inside only cat.