After some discussion on this panel about the possibility of liver cancer from the excessive use of Linatone, I wrote a letter to PetAg, the maker of Mirra Coat and to Lambert Kay, the maker of Linatone and told them that I had been told that the use of either product in excess could cause liver cancer in ferrets. I asked if either maker had performed any long term tests on animals and especially ferrets. I called PetAG at the 800 number on the product and the phone was answered by Dr. Monson. He was more than patient with me and answered all the questions I asked and followed up the conversation with a letter. Quite uncommon in this day and age. I thought this information might be useful. Phil Gentry 72701,[log in to unmask] PetAg., Inc. Science Nutrition Research Service October 15, 1991 Phillip R. Gentry Dear Mr. Gentry: Thank you for your letter of October 9th indicating a possible preference for Mirra Coat skin and coat conditioner for ferrets. I am not aware of excessively high levels of vitamin A causing liver cancer in ferrets. I have been advised that generally ferrets seem to develop cancer rather frequently but I am not aware of causative factors. Toxic levels of vitamin A typically result in bone problems and even skin lesions similar to those found in a deficiency state. The NRC publication, "Vitamin Tolerance of Animals", does not mention cancer as a result of high levels of vitamin A in poultry, swine and other production animals and pets. I'm enclosing some information on Mirra Coat including a semi-professional discussion on the nutrients found in Mirra Coat Special Care. The Mirra Coat Special Care powder is recommended at 1 level tablespoon (about 7 grams) per 20 lbs of body weight per day for dogs. If we assume that a ferret weights between 2 and 4 pounds, I would suggest 1/2 level teaspoon (about 1 gram) per animal per day. Our liquid product is more concentrated and should be used at 1/3rd the level of the powder. I believe that if the nutrients in Mirra coat are marginal in the diet you are feeding, you should see an improvement in skin and coat condition in 2-4 weeks. If there is no change, Mirra Coat nor other nutritional supplements may not be the answer under your current feeding and stress conditions. Very truly yours, William J. Monson, PhD. Vice President of Research and Development WJM/CM LAMBERT KAY Richard K. Fisher, D.V.M. Vice President Research and Development December 2, 1991 Mr. Phillip R. Gentry Dear Mr. Gentry: I am writing to respond to your question concerning Linatone Food Supplement. Although we have not conducted long term toxicity studies with Linatone in ferrets, our data with dogs fails to indicate any toxicity problems with elevated doses over extended periods of time. Linatone is formulated to provide slightly less than the National Research Council's nutrient requirements of laboratory animals. You can see that Mirra- Coat only provides 1/3 the recommended Vitamin A level. The scientific data does indicate that fat soluble vitamins (Vitamins A,D,E,K) will accumulate in the animal body over time if exaggerated amounts (20-30 times recommended levels) are consumed and produce toxicity or even cancer. Please be assured that liver cancer will not result from daily Linatone usage according to label directions. Sincerely yours, Richard K. Fisher, D.V.M. RKF:sp LAMBERT KAY, Division of Carter-Wal lace, Inc., P.O. Box 1418, Cranbury, New Jersey 08512-0187 Phone: 609/426-4800 TELEX: 510-685-4443 FAX: 609-426-4842 [Posted in FML issue 0238]