Cat who hates other animals

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I have a cat that's about a year and a half old and she hates all other animals, whether it's another cat or a dog. This past weekend, a friend asked if I could "dog-sit" for a few hours and when he and the dog walked in the door, my cat went into battle mode--she severely scratched and bit my 21-year-old grandson who was holding her--trying to get to the dog. She has done that with other cats also. The lady that gave me the cat had another cat and the one I took had almost killed the other cat, even though the two of them had practically grown up together. Does anyone have a solution for this? I'm ready to have her put to sleep.