spinal cord. The nervous system is amply supplied with blood, and 

 occasionally blood clots are found on the brain. The walls of the 

 stomach and intestines are often inflamed, and ulcers at the pyloric 

 end of the stomach are common in horses. 1 



Woolly loco affects not only livestock but is also known to result 

 in death to bees and prairie dogs. In Arizona, New Mexico, and 

 Texas where this plant is abundant large losses of bees have re- 

 sulted. These losses are more pronounced during dry seasons when 

 sweetclover and alfalfa flowers are scant and the desert flora fur- 

 nishes a large share of the nectar. In several places, losses are so 

 severe that beekeepers are forced to move their apiaries from in- 

 fested areas. Prairie dogs which eat the foliage of woolly loco 

 become stupefied and lazy, exhibiting many symptoms of locoism. 



Detailed and exhaustive chemical analysis indicates that the plant 

 contains a number of complex poisonous substances. From early 

 analyses in which barium compounds were found in loco material 3 

 it was concluded that loco disease was, at least occasionally, caused by 

 barium or its compounds, largely because that metal produces a 

 definite physiological reaction in animals similar, in some respects, 

 to those caused by loco. Later investigations, 4 however, tended to 

 disprove the theory that barium is responsible for the toxicity of 

 loco to range livestock. The amounts of barium present in loco 

 extracts barely more than traces were insufficient to cause death; 

 in fact, many other plants, not poisonous to livestock, contain similar 

 amounts of barium. Barium occurs in an almost insoluble form in 

 dried loco plants; and extracts from these plants usually contain 

 sufficient salts of calcium, potassium, and metals other than barium 

 to account for death. 4 



Although no specific remedy for loco poisoning has been discov- 

 ered, affected animals should be removed from the infested ranges 

 and fed a nutritious ration such as alfalfa and grain. 2 All animals 

 chronically locoed are usually constipated, hence food and medicine 

 should be administered to relieve this condition. 1 Alfalfa and oil 

 meal is a very common laxative mixture which is used frequently to 

 allay distress caused by locoisrn. Marsh et al. 1 recommend that, 

 where the constipation is severe, drenching with Epsom salts is 

 often efficacious. Cures if effected are slow, often requiring several 

 months. They state that cures among horses may be hastened if 

 daily doses of arsenic in the form of Fowler's solution are adminis- 

 tered, the doses being from 15 to 20 cubic centimeters (4-6 drams). 

 In the case of cattle these authors 1 recommend injections of small 

 doses (usually not more than three- or four-twentieths of a grain) 

 of strychnine to expedite recovery. Large animals may be given 

 as much as one-half a grain, the maximum dose, although, in some 

 cases, that is entirely too much. As a class, locos appear to have 

 long-lived seed and no method of cheap and easy eradication of them 

 has thus far been developed. Continuous grubbing, especially in 

 horse pastures, tends to reduce the stand and thus allay danger. 



3 Crawford, A. C. BARIUM, A CAUSE OF THE LOCO-WEED DISEASE. U. S. Dent. Agr., Bur. 

 Plant Indus. Bull. 129, 87 pp., illus. 1908. 



4 Marsh, C. D., Alsberg, C. L., and Black, O. F. THE RELATION OF BARIUM TO THE LOCO- 

 WEED DISEASE. U. S. Dept. Agr., Bur. Plant Indus. Bull. 24G, 67 pp., Illus. 1912. 



