A Syndrome Produced in the Dog by Inclusion of Oxidized Fat in the Diet

Abstract

The present investigation was undertaken to determine whether the chemical condition of the fat of a ration influenced the ability of an experimental animal to maintain health. McAmis, Anderson and Mendel 1 and Burr and Burr 2 have described a disease in rats due to the absence of fat in an otherwise complete diet. The syndrome is characterized by failure in growth, changes in the skin, especially of the tail and feet, and kidney degeneration. Burr and Burr 3 later reported that the disease could be prevented or cured by the feeding of linoleic acid. Evans and Lepkovsky 4 confirmed Burr and showed that glycerides of saturated fatty acids do not cure nor prevent the disease, but fatty acids containing more than one double bond have remarkable ability to improve fat-free diets. The conclusion was that certain fatty acids, essential for wellbeing, cannot be synthesized by the rat, although the rat is able to produce body fat on diets deficient in these essential fatty acids. Most of the work on fat feeding has been concerned with neutral fat or pure fatty acid. There have been a few contributions on the effects of fats altered in various ways. Powick 5 and Fridericia 6 showed independently that rancid fat destroyed the vitamin A of a ration when the fat came in contact with the vitamin-containing material.

The investigation to be reported deals with the effect on dogs of fat subjected to oxidative rancidity. A basal diet of purified foodstuffs planned to be adequate in all known dietary essentials was prepared: casein 16%, sucrose 55%, fat 25%, agar 2.5%, salt mixture 1.44%, and cystine .06%. It was very low in vitamins and was supplemented with Harris yeast concentrate and oscodal,† a cod liver oil concentrate.