I have 2- 10 year old cats (brother and sister) My Male cat throws up after he eats. Recently, I changed them back to canned food from dry food in an attempt to put a stop to this. It seemd to work a little, but he still does it. He has always been a thin cat, and has a hearty appetite. He acts normally, so not sure what the situation is. He turns into quite the pig when I oput the food out, sometimes preventing his sister from eating (he has always been like this). Any thoughts?