The postulation that peas might cause uroliths, as far as I know, has never been proven for cystine stones, but i have not read up on it in relation calcium oxalate ones or struvite ones. Often the use of foods w peas in them is stopped IF the ferret develops uroliths, just to be safest. Remember that ferrets can get several types of uroliths, and the causes differ. With cystine ones there is too high an intake of any of four amino acids, cystine or ornithine or lysine or arginine or some combination of those, for the ferret's personal genetic limitations. With struvite there is too much plant origin protein and in ferrets they are usually seen when a cheap food has been used though some struvite uroliths have other causes like bladder infections as the origin. I need to look it up to see if more is known, but recall the worry began with a strongly asserted but highly coincidental situation in a ferret w struvite stones, and the reason I recall that is because we shortly afterward had one w such stones so used that caution but later realized that it might be misplaced and in fact peas were not terribly high in any of the COLA grouping in things I read not long afterward. With cystine stones what has worked best for many years of health in the ones we had was keeping total protein below 35%. We have not had the other types of stones in any of our ferrets. Try the PubMed site. Saw palmetto turned out in several studies to not be highly effective in most human males and I have never read of a ferret w adrenal disease who actually was helped by it. See the PubMed site. Anyway, I am tired and fighting a virus, so go to PubMed and do some searches, and I hope I wrote this clearly enough. [Posted in FML 7656]