296 ESSENTIAL FATTY ACIDS 



Young puppies develop dermal symptoms after 4 to 5 months on a low fat 

 diet. The flaky desquamation of the skin and loss of hair is usually followed 

 by secondary infections. Alopecia and emaciation accompanied by a greasy 

 skin condition develop at later stages of deficiency. Dogs first develop an 

 excitable temperament and later become tremulous. This syndrome in dogs 

 can be prevented or cured by inclusion of unsaturated fats such as lard, 

 bacon fat, butterfat, or Crisco at a level of 16 % of the calories. One percent 

 of calories as linoleate or arachidonate caused definite improvement, but 

 did not provide a complete cure within 6 months. Dogs have been main- 



Fk;. !i. lM)ui-\\('ck-()l.l chicks on fat-free and 2% cottonseed oil diets. (From 

 Reiser. 18) 



tained on fat-deficient diet for as long as 6 years. Figures 8a and 8b show 

 a fat-deficient dog compared with his normal control. 



3. Chicken 



Early experiments by Russell and his coworkers, ^^ in which natural diets 

 were solvent-extracted to reduce the fat content, indicated that fat was not 

 needed in quantity for the growth of the chicken. The more recent work of 

 Reiser, in which synthetic fat-free diets were used, indicates that total 

 exclusion of fat from the diet of chicks causes slow weight gain and high 

 mortality. 1^ Chicks which received supplements of lard or cottonseed oil 



If* W. C. Russell, M. W. Taylor, and L. J. Polskin, J. Nutrition 19, 555 (1940). 

 16 R. Reiser, J. Nutrition 42, 319 (1950). 



