I need help on my fish. Please HURRY!!!!?

I have a small male tetra fish and i heard knocking and my cat got to him. She didnt eat him yet so i put him back in the bowl. He keeps on swimming frantically while facing the side of the bowl for a few minutes now. I saw a reddish color on his head but i dont know if that is blood or not and there is no blood in the water. What's WRONG!