DIAGNOSIS, DIFFERENTIAL DIAGNOSIS, PROGNOSIS 73 



of the particular poison, and some of the drug 

 poisonings (strychnin, belladonna, lead) are in 

 themselves characteristic. Poisoning with the al- 

 kaloids produces no lesions, and no poison, so far 

 as we know, is responsible for changes which are 

 observed in hog cholera. Common salt (sodium 

 chlorid) is especially poisonous for hogs that are 

 not accustomed to it, causing intense inflammatory 

 changes in the digestive mucosa, and congestion 

 of the meninges. Long continued feeding with 

 material containing soap and lye will produce 

 disease resembling chronic hog cholera. How- 

 ever, our task is usually to differentiate between 

 poisonings and acute hog cholera, and this pre- 

 sents no great difficulties if we resort to autopsies, 

 for none of the poisons produce lesions which re- 

 semble those observed in acute hog cholera. 



In suspected heat-stroke and lightning-stroke, 

 the history is an important guide. Heat-stroke 

 occurs most frequently in fat hogs deprived of 

 shade or water in hot weather, and in those 

 shipped in overcrowded stock cars, or subjected 

 to excitement or violent exertion during the sum- 

 mer months. The hair of hogs dead of lightning- 

 stroke may be seared, there may be arborescent 

 congestion or hemorrhage in and beneath the skin 

 at the point where the current entered the body, 

 and sometimes there are lacerations of the inter- 

 nal organs. Eigor mortis is not pronounced. 



