Unidentified Factors Essential for Growth and Hemoglobin Production in Foxes

Abstract

Fox pups and adults require an unidentified factor(s), distinct from the known crystalline vitamins, for normal nutrition. The deficiency syndrome produced by a lack of this factor(s) is characterized by anorexia, loss in body weight, depigmented, matted underfur, suboptimal hemoglobin levels, reversal of the neutrophile-lymphocyte ratio, fatty, light-colored livers and death. Supplementation of the ration with 10% fresh raw liver or 50 ml per day of raw whole milk corrected the deficiency symptoms. Preliminary evidence indicates that there may be more than 1 factor in fresh liver required by the fox.