I have a 3 year old-female-indoor-cat and she has a problem. Her problem is she will eat a small amount of food then vomit. This has been an on going process that has left us and the vet clueless. She has had every test that is possible and they haven't found anything wrong. She did have tapeworms once before and she doesn't anymore since taking the medication which was a year ago and we know for sure that she does not have them now. When we clean the litter box we check for worms but we find nothing (I know that doesn't sound appealing but we have to do what we have to do).We have tryed changing her food (gradually) a few times but that didn't seem to work. Not only is the vomiting a problem (i know it is a major concern) but she also turned aggressive for some reason. She would come out of nowhere and walk up to one of us and then she would bite and scratch. She does play and she seems fine otherwise. If there is anyone who is having the same problems or anyone with any advice, please let me know. Thank you!