When I first adopted my cat from humane society, she was eating Science Diet dry. She did fine. Then all of a sudden she wouldn't chew it up and when would throw up. So I started giving her only wet. I tried to give her a different brand of dry as a treat, just two pieces and she threw up again because she wouldn't chew it up. And she would throw up 2 or 3 times. Is it because she doesn't chew up the dry, or could there be something wrong with her.