American Journal of Clinical Nutrition, Vol 6, 159-163, Copyright © 1958 by The American Society for Clinical Nutrition, Inc.

Calculi and Kidney Calcification from Feeding Milk Diets to Rats and Hamsters

¹ From the Animal Nutrition Laboratory, Cornell University, Ithaca, New York

Three studies in which rats and hamsters were fed diets composed of fresh milk supplemented with trace minerals, sodium bicarbonate, and in some cases, sucrose, indicate that the female rat is very subject to calcification of the kidneys while the male suffers from calculi of the bladder. The Syrian hamster is difficult to maintain on fresh milk diets but develops neither calcium deposits in the kidneys nor calculi in the bladder. No evidence was found that these deposits could be dissolved after rats were changed to another diet for three months. The oldest rats were continued on the diets for a year while the hamsters in the longest study were fed the milk for 11 months. The white rat seems to be a very useful species for the study of the effects of Sippy diets and methods of reversing calcification of kidney tissues and calculi of the bladder.

To prevent complications from hair-balls in the stomachs of experimental animals, it seems useful in studies of liquid milk diets to feed a gram of cellulose per day to each animal. This can be mixed with sucrose and fed separately but such animals suffer from decay of the teeth. In neither rats nor hamsters are the teeth affected if sucrose is dissolved in the milk and not fed separately.