Sorry it has taken awhile to answer the questions about Brewers yeast/chromium and insulinoma treatment. I had a computer problem, but I am back up and running again. Seems like there are 3 basic questions: 1) is chromium good to give to insulinoma ferrets(no), 2) is chromium safe to give to healthy ferrets(yes), and 3) can chromium possibly prevent insulinomas in healthy ferrets(maybe). I will try to clear up some of the general information first, then answer those 3 questions. Brewers yeast is a common ingredient in pet foods because it provides some of the B vitamins (esp. Thiamine B-1) and chromium. Thiamine is a very important B vitamin that is needed by ferrets and most mammals. Chromium is the part that causes the confusion. 1) Chromium is NOT a good thing to give an insulinoma ferret because it actually lowers blood glucose levels. Chromium also has some insulin like properties. Clearly we do not want to lower an insulinomas already low blood glucose level. Nor do we want to give something that acts like insulin when there is already to much insulin being produced by the insulinoma. Chromium is a good thing to give to diabetic people and pets, but diabetes is rare in ferrets. 2) Yes chromium is safe to give to ferrets without insulinomas. Again brewers yeast has a lot of the needed B vitamin thiamine. Chromium does not cause problems in the healthy ferret. 3) Can chromium prevent insulinomas? This is a good question that needs further research. Since chromium helps to lower the post meal glucose surge, it may help to prevent stimulation of the pancreas that occurs after eating a meal with carbohydrates in it. It is this overstimulation of the pancreas after eating carbohydrates (sugary treats, rice, etc.) that cause an insulinoma to form. If we had a ferret diet with a low carbohydrate level (10%) instead of the 20-30% carbohydrate diets that we currently have, If we had a diet with carbohydrates that produced lower post meal glucose peaks (sorghum, corn, barley) instead of rice that produces the highest post meal glucose peak, If we had a diet with enough chromium to lower the post meal glucose peak, then we might prevent insulinomas from occurring in ferrets. Again this is an area that needs further research. Based on what we currently know, chromium is a good thing for healthy ferrets, but a bad thing for ferrets with an insulinoma. Hope that clears up the confusion, Jerry Murray, DVM [Posted in FML issue 3446]