252 PRINCIPAL STOCK-POISONING PLANTS 



Nebraska and eastern Oklahoma, and south through Texas, into 

 Mexico. Woolly loco does not usually grow so abundantly as 

 Lambert's or white loco and certain other species, yet it may cover 

 several acres. It grows as a rule in patches, on adobe soil, 

 and in depressions rather than on elevated ground. 



Losses of Stock and Animals Poisoned. — Loco weeds are 

 among the most destructive of all the poisonous plants. Losses 

 in regions where purple loco is the only poisonous weed are almost 

 entirely among horses, mules, and sheep. Cattle seldom crop 

 the plant. Horses do not usually eat purple loco if other 

 forage is plentiful, but they may form the habit if forced by 

 lack of good forage. The use of the plant generally results 

 fatally. White loco, on the other hand, is eaten more readily 

 by horses, mules, cattle, and sheep, especially where palatable 

 grass is scarce. Some animals leave loco for grass when the 

 latter becomes green, but others develop a strong liking for 

 loco and continue to eat it regardless of the presence of other 

 feed. They will usually, however, lose their fondness for the 

 plant if kept away from it. The effects of eating loco depend 

 largely upon the individual animal. Some animals eat a lim- 

 ited amount of the plant at certain times of the year for a number 

 of seasons without apparent harm, but others die \vithin a few 

 months or in a few weeks. Losses from loco poisoning are 

 heaviest among young sheep and horses, as older animals rarely 

 acquire the loco habit except where good forage is scarce. 



Symptoms of Poisoning. — Loco poisoning may be acute, 

 resulting fatally within a few days, or it may be slow, working 

 for months or even as long as a year. The effects of the poison 

 are cumulative; animals never become immune to it. The first 

 symptoms of loco poisoning are stupidity and general loss of 

 condition. The animals show marked lack of muscular control 

 and become very nervous and excitable. The gait is irregular 

 and staggering, the eyes are glassy, and the sight is impaired 

 or lost altogether. A rough, shaggy coat is characteristic. 

 The loss of muscular control causes the animal to act in an ab- 

 normal manner, apparently seeing things incorrectly or as the 

 exact opposite of what they are. For example, a horse will 



