DISEASES OF THE HEART 55 



quite noticeable. The pulse-beats are quickened and 

 somewhat irregular, and the animal may appear rest- 

 less and anxious. Excitement and exercise some- 

 times cause this condition, or it may occur in con- 

 nection with some digestive disorder and a spasm of 

 the diaphragm. It may also occur in acute heart 

 disorders. 



Spasm of the diaphram is quite common in pigs. 

 It is due to an irritated condition of the nerves (phren- 

 ic) going to the diaphragm. Digestive disorders, 

 especially overloading of the stomach, and lack of 

 exercise are the main causes. It is not uncommon 

 for a large number of pigs in the same litter or in 

 the same, pen, when too closely confined, to have 

 thumps. 



Symptoms.- — The most prominent symptom oc- 

 curring in thumps is a sudden jerking movement of 

 the flank. This is very noticeable when the pig is 

 standing quiet, and may be of such force as to 

 move the body backward and forward. The shock 

 of the contraction of the diaphram is accompanied 

 by a sound in some cases. The spasmodic contrac- 

 tions do not occur regularly, but irregularly, and 

 are much more frequent at times when the stomach 

 is full than when it is empty. 



The digestive diseases, as well as the thumps, in- 

 terfere with the growth and thriftiness, and the 

 pig becomes more or less stunted. Sometimes they 

 lose flesh quite rapidly and become quite thin. 



The course of the disease is from a few days to 

 several weeks. 



