I am just catching up on the FML, and I think you may have misunderstood Dr. K's comments about taurine. Dr. K is one of the foremost vets studying degenerative retinal disease, and he may have suggested that ONE of the causes is lack of taurine in the diet, and he should have ruled that possibility out for you because you feed Up a premium quality pet food. MEAT is a natural source of taurine and Iams is a premium quality meat based food. I have never heard of any vets recommending a taurine supplement for an animal being fed a premium diet, so I would tend to think your ferrets optical problems are genetic, not diet-related. Call Iams and ask what the percentage of taurine is in the package. They don't state it on the label because it's naturally occurring and in sufficient quantities for cats. If it's sufficient for cats, wouldn't you be able to extrapolate that info and assume that it would be adequate for ferrets even if they required a higher quantity? (You can't get higher taurine than pure meat content in a feral state, why would a domestic state of ferrets require higher taurine?) The # for Iams is: 1-800-525-4267. They'd be happy to provide you with their feline research, but I don't think they'll have any specific mustelid information. The other place you can check, is a state/provincial/national veterinary school. They can tell you what their ferret diet formulation consists of and why. I know that the U of Saskatchewan in Saskatoon was testing a corn-based diet. Why, I have no idea, but you could certainly ask them. -=-=- [log in to unmask] The Territorial 3 and the Kitty (what rhymes with 3 here? hmmm) [Posted in FML issue 1536]