Actually, I see no problem except for ferrets with certain medical problems, and those same risk factors are shared by a number of other foods. There are past discussions which can be looked up on why peas might be a problem for certain ferrets. The difficulty may be that the individuals who are prone to getting cystine uroliths could have specific aspects of the peas act together to create these BUT ANY HIGH PROTEIN FOOD ALREADY POSES A RISK FOR THOSE INDIVIDUALS. That is because the individuals who have cystine crystallize out have a genetic kidney problem. When their bodies get too much of ANY of four amino acids (amino acids being the building block of proteins), the so called COLA Group -- which is comprised of cystine, ornithine, lysine, and arginine -- their kidneys cause cystine to precipitate out and then it forms crystals which may become slush or may become stones. Either can cause a blockage, usually at the urethra leading from the bladder, and can be life threatening. But again: a high protein diet already poses that risk for the individuals who have that genetic vulnerability. Those individuals need to be on a 35% or lower protein diet and a few need meds. Ferrets get multiple types of uroliths, which literally means urinary stones, and the treatments for some are opposite of the treatments for others. For example, the most common stones, struvite -- which can be from a diet too high in vegetable matter or from infection -- often call for acidifiers but giving acidifiers to a ferret with cystine uroliths is going to worsen the problem. That is why a ferret with stones or slush needs those checked by a urolith lab and why the urine pH also needs to be checked. How common are these ferrets who are placed at risk by high protein diets? If you buy from a breeder with it in the line then do not give high protein diets or certain other possible risk factors. In over three decades with ferrets in our family, most from commercial breeders originally we have had two ferrets with this vulnerability be expressed. Of course, high protein diets are a RECENT thing, so before those high protein diets existed we might well have had vulnerable ferrets who simply had a low enough protein diet to not get the stones. In other words, how common the vulnerability is is an unknown, but most ferrets probably will not have it. If the urine pH is low then the individual might be at higher risk. On the pH scale low is more acidic and high is more alkaline. Different things precipitate out more easily at different pH levels. Cystine precipitates out with more acidic urine and struvite precipitates out with more alkaline urine, for example. Years ago a British biochemist with knowledge I simply do not have, presented a mechanism through which a diet too high in sulphur (also accurately spelled sulfur) and something else that escapes my memory might also contribute to forming cystine uroliths. Okay, I just looked it up. She said that when items high in the amino acid methionine are eaten along with ones high in sulphur that the body utilizes the sulphur to convert some of the methionine into more cystine. Again, any diet high in protein will be likely to have high protein building block -- amino acids -- content. She wanted to retain her anonymity so sent it to me before I retired from being an owner and moderator of the FHL. I ran it by a few vets. The only one who did not feel comfy with it replied months later, but that vet was also not familiar with the COLA Group info which had been shared by three noted urolith experts, so not up on the topic in general. Anyway, the same interaction creating more cystine using methionine and sulphur could be caused by having two foods with one high in one and the other food in the other. For other ferrets who have kidney disease high protein itself can be hard on the kidneys, again IF they they have kidney disease, Organs are fine. Actually regular chicken byproduct meal FROM A REPUTABLE ORIGIN which also contains some skin, and a tiny bit of feathers, etc is usually fine. I forget which nutrient it is but chicken feathers are actually so high in one nutrient that they are used to make it as a supplement. The problem is that some low grade ones have far too many feathers instead of better content, also, some nations do not control what us added and what is given to food animals very well. Organs are not only good protein sources but also are great mineral sources. Muscle meat itself is piss-poor in a range of needed nutrients which can be found in the organs. I am copying the FML because a similar topic came up there recently and this covers holes in that discussion which not everyone will have looked up. [Posted in FML 7971]