POISONOUS PLANTS. 101 



Conditions affecting activity of the poison. — Old horses are 

 less susceptible than younger ones. Horses having good grain 

 feed resist longer than those that are insufficiently fed ; the trouble 

 seems to be caused almost entirely by the plant when fed with 

 the hay, rarely when eaten in a green state. 



Treatment. — Administer a cathartic and remove the cause of 

 trouble by discontinuing the use of the hay containing this 

 plant. 



WILD CHERRY LEAVES. 



There are several varieties of w'ild cherries which cause 

 poisoning, particularly choke cherries and black cherries. The 

 poisonous property is probably due entirely to prussic acid. The 

 common black cherry seems to be far more frequently the cause 

 of poisoning than any other species. The leaves that grow on 

 succulent shoots seem to be most actively poisonous. They are 

 less poisonous when wilted, and there seems to be considerable 

 doubt as to whether they are poisonous at all when actually 

 dry. 



Symptoms. — These are the ordinary symptoms of prussic 

 acid poisoning and develop very rapidly. There is a very weak 

 pulse, difficult breathing, expression of fright, with prominent 

 eveballs, rapid breathing and death from paralysis of respiration. 

 There is usually a noticeable peach odor in the breath. 



Treatment. — When animals take a fatal amount of the poison, 

 death is sudden and there seems to be Httle use in attempting 

 treatment. 



