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Cats/Unusual behavior from sibling


I have 2 cats that are about 7 years old, they have lived together for all of the with me, a couple days ago, the female has not wanted anything to do with her brother, and if they come in contact with each other, she will hiss, and stare, when she fist start acting like this, she wanted to fight, the male would just go on his back in defense, but she would be pouncing on him with everything she had, and seems to want to fight to death, all out claws and everything, they have always usually loved each other, groomed each other, so this seems very odd, she seems a little skittish around me, but once i start petting her she's fine, would you know, what is going on with her, and does it mean there is something wrong with her medically, or is she just very upset with him about something?

any change in behaviour is always worth investigating. Just in case it is caused by an underlining illness.

if I were you I would have her checked by a vet to at least rule out any possible illnesses. Always better to be safe than sorry.

if all is Ok then it must be due to perhaps a fright she has received recently which has upset her to the point that she is taking out her fear on another cat. this is not uncommon and is known as aggression trauma. normally the only way to try and cure this is to help the cats  rebuild there confidence in each other again. this is done by using the introduction procedure described here


It may seem like a lot of hard work but it really si worth it to have a happy home again.

best wishes Kate


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Kate Tilmouth


I can answer most day to day cat problems encountered by owners. I have a good understanding of cat behaviour and problems which may arise from changes to their daily routine. I can advise on cat training including litter training and general day to day cat care issues. I am not a vet and therefore cannot answer medical questions.


I run my own cat website at and have been a dedicated cat owner for over 20 years. I have encountered many different cat problems and situations and feel that i have a good understanding of cats and cat ownership.

I am a platinum member of Ezinearticles where i write mainly cat related articles.

Educated to High School level and have since worked for many years in a customer support based environment, gaining vocational qualifications.

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