Purina — dog chow high protein can dog food beef

I feed my dog a half a can of your High protien dog food. As I was saving the other half, I noticed a white chunk of something in with the food. It also streaked white. My dog was already eating what I put down. When I saw this, I stopped him and threw it out. It smelled fowl, really bad, and my dog is now sick. I'd like to know what this was! It looked like mildew and smelled worse.