The invention relates to compositions for preventing and/or treating cardiovascular diseases in felines with hyperthyroidism wherein the compositions comprise from about 0.07 to less than about 1 mg/kg iodine and/or from about 0.1 to about 1.3 mg/kg selenium. The invention also relates to methods for preparing and using such compositions, articles of manufacture comprising such compositions, and means for communicating information about such compositions, methods, and articles of manufacture.