If your cat is normally calm and friendly and suddenly becomes aggressive, you need to look for things that trigger that aggression.
First, look at any changes that have been made to her environment. Did you make changes? Maybe you’ve added a new cat to your family? Have you had to leave her alone for longer periods of time? Is she now exposed to dogs or kids? Are there new cats in the neighborhood? Even in-door cats get jazzed up when they see a cat outside the window, and attack the closest in-door cat they see.
Bruce (Kami Kazi) Lee, Feigning Calmness.
My most aggressive cat. If it runs, he chases it.

Has you cat suddenly become food aggressive? Food aggression can happen in cats just as it does in dogs. If this appears to be the problem, feed her in another room from the other cats. I have 12 indoor cats and even though they have hard food out 24 hours a day, 7 days a week, I give them a soft food treat once a day. They each get their own dish for this treat, otherwise, most of them get a little aggresive.
If you can’t find the trigger for your cat’s new aggression, consult a doctor. You should take her for a complete check up. Aggressive can be a symptom of a health problem. Cats do not like to show weakness (i.e. illness) so they either hide or show more aggression as a defense mechanism.
If there doesn’t seem to be an environmental problem you can change or health problem, you can consult an animal behaviorist for insight into your cat’s problem.
Purrs, Frankie
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