Huh, fascinating. I used to feed my cat Purina Cat Chow. Her vomiting increased this spring and after a couple of months of that I took her to the vet. He said cat foods based on corn often irritate cats and suggested I try one of a couple of corn-free brands, so I switched her to Wellness (one of the brands he suggested, I forget what the other one was) and she stopped vomiting (well, went back to her previous rate of once every few months).