He has been vomiting once or sometimes twice a week for a few months. (Before this his vomiting was very infrequent--considered normal.) Usually, the vomit is pure, barely digested food. Sometimes, though, it is liquidy-yellow. One time I think it had a green tint. He began a new food approx. 6 mos. ago--Science Diet Lite, after his vet suggested that he was a bit overweight. (I'm not sure if he has lost any weight. Maybe he is a little thinner.) Before this he was eating Innova all-natural food for many years. I am wondering if he is eating too much of the Science Diet, trying to fill up (since it is lite), hence throwing up. I'm just not sure about the liquidy vomit, though. Our other cat, almost 3 years old, has reacted fine to the food change. Should I be concerned? Thank you.

