178 SHEEP DISEASES. 



senic, are used to eradicate predatory animals or 

 squirrels, and not infrequently are distributed 

 where sheep have access to them or are washed to 

 such locations by surface drainage. 



In treating cases of poisoning, one should re- 

 member the three cardinal principles of toxicology 

 which consist in administering: 



First: Chemical antidotes; substances that 

 change the composition of the poison into some- 

 thing inert. 



Second: Mechanical antidotes; substances that 

 surround the poison and protect the absorbing tis- 

 sues. 



Third: Physiological antidotes; substances that 

 antagonize the action of the poison by neutralizing 

 its effects on the animal. 



Keeping these facts in mind, one can often use 

 ingenuity in selecting substances with which to 

 treat poisoned animals, where the proper anti- 

 dote is not to be had, a condition that is often the 

 case since sheep are usually found in the most 

 inaccessible parts of the country. 



A. MINERAL POISONS. 

 1. Acute Lead Poisoning. 



Acute lead poisoning is rather rare in sheep, 

 but it sometimes occurs in early spring. 



Symptoms: Colic, with bloating; suppression 

 of the urine ; slow, wiry pulse, with labored breath- 

 ing; gradual weakness, followed by convulsions 

 and death within a few hours. 



