i have 3 cats that i have had for 4 years now. two of them are brother and sister and the other is a calico. they have all lived in peace and harmony with no trouble what so ever. about 3 weeks ago my calico all of a sudden just could not be around my male cat. my calico would immediately start viciously attacking him as soon as she saw him. he was neutered approx 3 years ago, while both females remained un-spayed. she would attack him till he was bleeding and pee-ing himself as he was running away. while this was going on our other female would join in and end up fighting as well. i called the vet and she told me i would need to get my calico spayed and that would solve the problem. it didn't help, and now she even attacks the other female. she just fights and fights. we have had her separated from them going on 3 weeks now. we have tried the feliway, the hormone collars, bathing all 3 cats, and reintroducing her to the others with no avail. she acts completely normal when she is alone. she shows no signs of distress or anger. please help me anyone, hoping to resolve this issue because of our relationship with her. she is my partner and follows me around everywhere.