My sister has had her kitty for about 9 months and it is the most awful cat I have ever encountered. She growls, bites, and scratches everyone besides her and her boyfriend. But just last week, Seala (the cat) bit my sister and penetrated her skin, it will probably leave a scar. Is there anything she can do to put a stop to this? I know cats can be very independant and stubborn. I told her to get some blood tests to rule out any medical condition. Any more suggestions I can give her?