I have a cat that is 13 and in good health. He likes to eat grass, which he will throw up from time to time, but i dont worry about it because he has always done it and i have seen many cats do it. But what worries me is now when he does throw up, he falls over. He cant stay upright. It scares me, what if he were to choke when i am not around. He is fine any other time, has good balance, can jump up on things, he roles on his perch and doesnt fall off. So i cant figure out why now all of a sudden when he throws up he falls over. Has any one else had this problem, is it because he is older ?