Posterior Paralysis in Swine. 



427 



One of the 5th pair of twins was completely thyroidectomized 

 when 23 weeks old. Subcutaneous treatment with thyroxin was 

 begun 13 weeks later and continued for 15 weeks. 28 weeks later 

 the electrocardiograms were taken. They showed a distinct ad- 

 vance toward the normal from the cretin type. 



The expenses incurred in these experiments were defrayed by a 

 grant from the Heckscher and Sage Research funds, made to Dr. 

 Simpson. 



209 (1956) 



Preliminary studies of " posterior paralysis " in swine. 



By L. A. MAYNARD. 



[From the Department of Animal Husbandry, Cornell University, 

 Ithaca, New York.] 



A study is in progress of the frequently occurring trouble in 

 swine, commonly referred to as "leg weakness" or "posterior 

 paralysis." Some preliminary observations are here described. 



In connection with another experiment, a group of 4 pigs, each 

 about 12 weeks of age, were fed in dry lot for 90 days on a ration 

 consisting of 1 part of yellow hominy feed and 1.4 parts of pas- 

 teurized skim milk, together with a mineral mixture made up of 

 charcoal, ground limestone and common salt. 



At or near the end of the 90-day period, 3 of the 4 pigs devel- 

 oped symptoms of trouble. A stiffness of the hind legs first be- 

 came evident. The skin became dry, scaly and covered with 

 large, livid spots. The stiffness increased, accompanied by pain. 

 A swelling of the knee joints was noted in one individual. Finally, 

 paralysis developed in the hind legs of 2 of the animals, they being 

 able neither to rise nor to stand. A rapid loss in weight set in at 

 this stage. 



At the close of the 90-day period, the writer changed the diet 

 for 2 of the pigs. One of them, number 122, was unable to rise 

 or stand, was obviously in pain and was losing rapidly in weight; 

 the other, No. 107, was markedly stiff behind but was still able 

 to walk. To the hominy-skim milk ration, was added 4 ozs. of 

 carrots per animal daily. The mineral mixture was replaced by 

 precipitated bone meal, precipitated calcium carbonate and salt. 



