I have a 7-yr-old fixed male cat. He's had a lot of vomiting problems over the years, until I switched him to an all-wet-food diet. Once I did that, pretty much the only time he threw up was when he had fur balls. And it seems like that's where the current problem began...
It seems like he shed significantly more than usual this summer, which was especially strange considering that we had a very cool summer. I brushed him every day, but he still threw up fur balls pretty much every day. Every once in a while he would yowl in pain, so I thought he might have a lot of fur in his stomach. So I started giving him fur ball treatment every day (which he loved and actually served as a reward that made him more cooperative during brushing).
Once I started giving him the fur ball treatment, he still threw up fur balls everyday, but he wasn't yowling in pain anymore and he seemed more playful too. That is, up until about a week ago. Suddenly, he stopped throwing up, and I assumed that was becuz he was shedding less as we approached the end of summer. I also noticed that he was leaving a of food in his bowl (though he would still meow to be fed), and that he was getting even skinnier than normal. I finally figured out that was he was doing was licking the "gravy" off the food but leaving the meat. I watched him eat and he got a piece of meat in his mouth, chewed it a couple times, and spit it out.
So at this pt, I'm not sure what the problem is. I thought his teeth might be hurting and that's why he didn't want to chew, but they look ok. I also thought that he might still have fur in his stomach and the "liquid diet" he's on makes it hurt less somehow. I gave him the fur ball treatment again, but he didn't throw up anything. He's not producing much stool, but what he is producing doesn't have any fur in it. I also got some liquid food for nursing kittens to make sure that he's at least getting his nutrients until I figure this out, but he wouldn't eat it