4 - 5 months kitten

[elieay]

Hi, my kitten is 4 to 5 months old and does not live with another animal in the home, she has recently met her brother that i will be looking after whilst the owner is away.  my kitten would not interact with her brother and she has become aggressive and attacks.  She always gets paranoide when she hears him even when his not around and hides most of the time.  She is constantly alert searching for him. When she is chased by him they stay stable and stare because she fears to turn to run.  Talking about the male kitten, he is a sensible kitten and tries to go close to her and sometimes cries when i put them apart.  I thought it could be the fear of mating? Could you please tell me what the problem could be in this situation?

[elieay]

the 1st paragraph was not posted at first which partly helps answer my questions. thank you.

[Aleda M Cheng, D.V.M., C.V.A]

Since they are both not spayed or neutered and their ages are close to approaching puberty there may be a hormonal component to the problem.   Your female may be going into heat early and stimulating the male.  Cats can go into heat as early as  5 months of age.  If this is the case than spaying and neutering will help the problem.  Also, if they have gone into puberty, there is a chance that the brother could get her sister pregnant, which is ill advised.

I do not know how long you will be caring for the brother but I would keep them separated until they are spayed and neutered.  

If the problem is not related to hormones than they should get along eventually, but it may take some time.