Cats are fighting (please read the details)?

Question

i am asking this for a friend so all the info i list is all the info i know about. i'll try to remember it all.

one is male and one is female
they are both fixed
they are from the same litter
they have lived together for eight years
The only other time this has happened was last year, which lastes a 3 month period around this time.

i'll copy and past some things my friend said:

"She comes to my door and scratches and cries at it until i get up and let her in. And then she proceeds to make all kinds of noise..."

"She walked right up to him, hissed in his (other cat) face and walked into my brother's room. Poor Baby was like "What the **** did i do?". The little guy's trying to be nice, but for some reason, she won't get over it. She also doesn't understand, WHY she can't be out of my room at all hours. Until i open the door. Then she sees Baby, hisses and growls at him, turns around and goes to sit on my computer chair."


out of space, i'll put the 2 questions on the "ADD DETAILS"

-=-=-=-=-=-=-=-=-
why would they be fighting all of the sudden?

what can she do to stop them from fighting?
-=-=-=-=-=-=-=-=-

thank you for any help you can give.

Answer 1

Soft claws sill keep the damage down. Make sure both cats are fixed, and use a squirt gun when they fight.
http://www.softclaws.com/
A

Answer 2

There can be many reasons, so i can't give specific advice. Except for this: either see a behavioural specialist (some vets will refer you to one) or go to www.clickertraining.com, where the training methods might help, at least some. If you don't see an effect soon, go to the specialist.
In the mean time keep the cats separated, at least when they are alone.

Answer 3

Cats often hiss at each other when they are in pain because they dont want the other cat to get too close. I think she should have a check up with the vet to see if there is a underlying problem

Answer 4

Some cats just wont get along. Try this when she hiss tell her no or use the spray bottle method. You just have to train her.

Answer 5

cats can be ilke guys, they fight once or twice then they will be friends. yr girl might just not want another cat in the house, and she thinks he's steeling her people that are hers. you can make them duke it out but brake it up once it get t rough. but for the door thing do what you can or bring her when you go 2 bed

Answer 6

Sibling rivalry!

Answer 7

go vet your cat became agressive read a book for library

Answer 8

I learnt a lot from your query & answers there-to