Dear Malcolm; I think you've learned that dog food is not at all suitable for ferrets. They will die on it as it's protein is so low. The highest grade of cat food you can find, with the greatest proportion of meat as the protein rather than vegetable is called for. The calcium suppliment is good, but I would think should be used under a vet's guidence so you don't cause any other problems from possible over dosage. You might even see if you can get some Totally Ferret brand food that would be good for your situation as it is highly concentrated. IT is so concentrated, that it is not recommended as a sole diet for adults say over the age two. Actually, since ferrets imprint early on what is food, it's good to offer a variety while they are young, that way they'll be more open to other foods later on. There is a case of a lady who fed only one food to her ferret, and later the company stopped making the food. The ferret could not recognize anything else as food and starved to death. I don't know this personally, but have not heard anyone call it wrong either. T.F.'s US # is 800-843-1738 or 513-890-7784. Fax=513-890-7799. I just talked to them & either Pat or Tom Willard the oners would be happy to consult with you and help out in any way they can. Their address is 510 Green Manor Ct., Dayton, Oh. 45415. I'd not wait for the mail but rather call to expedite things since your kids are in serious shape. They said they are hearing some very good stories of how the food has and is helping heal a variety of situations. Best wishes, Gary Violence is not strength, Compassion is not weakness. From Camelot. [Posted in FML issue 1455]