“Some syndromes, such as steatitis [Yellow Fat Disease] in cats, result from an increased requirement of vitamin E in diets that contain large amounts of polyunsaturated fatty acids, and these diseases will only respond to vitamin E administration. Deficiency syndromes in animals owing to pure Se [selenium] deficiency are infrequent and have been produced mainly by laboratory studies utilizing extreme deficiency conditions. Other factors that may affect the occurrence of these deficiency diseases are concurrent dietary deficiency of S[sulfur]-containing amino acids, bioavailability of different forms of dietary Se, intake of compounds that antagonize Se (e.g., silver salts), and exposure to various prooxidant substances (e.g., iron compounds, oxygen, ozone, and various drugs).”