Many Greys have been forced to survive on the horrid 4-D foods and it can leave them with lifelong issues and complications. Pancreatitis is one problem and the off shoot to that is the terrible big "D" (diarrhea) I've had numerous Greys in my life and discovered quite by accident how to keep "D" at bay. It's basically harmless and my greys get it daily weather they need it or not. It's called TYLAN. When you get it from the vet, it's a major expense. Less than an ounce of this powder cost me almost $50.00. I got a 100 Gm approximately 8 ounce bottle from Foster and Smith for far less than that. It isn't a required prescription product and you can purchase it from pharmaceutical companies for very cheap. It's just so much easier putting 1/16th of a teaspoon in their food twice a day and not having that dog awful odor smacking you in the senses in the middle of the night. Then you discover the 'accident' right on the carpet where everyone walks, because you just walked there yourself! It's also sold as "Angel Eyes" for spaniels that leave marks from their eyes tearing all the time. It's also given to chickens, cows and other farm animals to keep them on the less smelly side of life.