LECTURE XXIV. 



STOCK POISONING. 



It is probably safe to say that stock poisoning, except by- 

 poisonous plants, is very rare. Occasionally cattle are poisoned, 

 by taking- boiled linseed oil or eating Paris green ; horses are 

 sometimes poisoned by boiled linseed oil, given by mistake as 

 a medicine. 



BY POISONOUS PLANTS. 



General considerations. — Poisoning by plants quite often oc- 

 curs early in the season, or when stock is put on pasture to which 

 they have not been accustomed, and especially when the animals 

 are hungry at the time of change. The effects seem to depend 

 to a considerable extent upon the amount of food in the stom- 

 ach and upon the physical condition of the animals. Hungry 

 stock may eat plants which would not ordinarily be taken at all, 

 and the total amount eaten has very much to do with the serious- 

 ness of the illness. 



Cottonseed meal has an undeservedly bad reputation. It is 

 very probable that the trouble for which it has been blamed, is 

 due to the error of using too large a proportion of this food, 

 which is very rich in nitrogenous elements, and not to any poison 

 which it contains. 



Three groups. — Poisonous plants may be divided into three 

 groups. First, those causing very sudden death — such as sor- 

 ghum and wild cherry leaves, which contain prussic acid. Sec- 

 ond, the irritating poisons, such as the bracken fern, water hem- 

 lock, wild parsnip and wild mustard. Third, poisons which pro- 

 duce profound disturbance of the nervous system, such as paraly- 

 sis, interference with the special senses, delirium, disturbed heart 

 action, and insensibility. Among these are included jimson weed, 

 loco weed, poison hemlock, wild parsnip, larkspur and laurel. 



