My vet has been out of town all week taking continuing ed classes but he gets back tomorrow and I'm going to call and talk to him about this. I was relieved when the pet food tragedies occurred because I saw that Purina wasn't on the list. My old vet , who has since retired, started my cats on Purina 16 years ago; he told me that they were the best then and so I never changed foods. None of my cats have ever had a problem w/it, they gobble it up, so I saw no need to try something else. If my vet has anything to add when I talk to him, I'll be sure to post it.