LEGUMINOSAE OXYTROPIS 



569 



universally present in the intestines of sheep, and under ordinary conditions do not cause 

 any recognizable disturbances. The disease of sheep known as "gid" is not to be mis- 

 taken for the loco disease and, furthermore, is not prevalent in this country. No indica- 

 tions were found during the post-mortem examinations that the walls of the stomach were 

 .affected to any appreciable extent by the action of loco weeds, although these plants were 

 invariably found in the stomach contents of such sheep. In the majority of cases no ap- 

 parent changes have been produced in the spleen, liver, or kidneys. In some instances a 

 slight congestion of the intestines was noticed. The cerebjal membranes were in all cases 

 somewhat congested. This condition is probably one of the immediate physical causes of 

 the mental excitement exhibited by locoed animals. Post-mortem examinations of locoed 

 liorses disclosed the same conditions as those found in the sheep. 



They made a number of experiments with a young Belgian hare and other 

 rabbits, using the water extract of the leaves, and it was shown that this was 

 not an acute poison if from 10 to 15 cubic centimeters of the liquid were 

 administered. An acute case of loco disease was observed in an old ewe with 

 a lamb at her side. She had eaten considerable quantities of the white loco weed 

 (Aragalus spicatus-Orytropis spicatus). A slight locomotor ataxia was man- 

 ifested. The eyelids twitched rapidly and there was a slight champing of the 

 jaws. Each attack lasted from 1 to 2 minutes, and the intervals between the 

 attacks were about 5 minutes. 



The lips and eyelids twitched violently and the jaws were moved upon one another 

 with such force that the sound could be heard for a distance of 200 yards. 



Similar symptoms were observed in the lamb, which died in the afternoon. 



Locoed sheep are exceedingly difficult to herd. 



It is the universal experience of sheep raisers that locoed sheep are exceedingly diffi- 

 cult to herd. The sheep may, without a moment's warning, stray away from the band, 

 -each one in a different direction, and it is easy to understand how nearly impossible it is 

 to prevent such a band of sheep from becoming separated. Besides giving the herder 

 much trouble in directing the course of the band on the range, locoed sheep alsc refuse 

 to enter the corral at night, and under any and all circumstances may suddenly manifest 

 perplexing stubbornness. 



These writers did not observe many locoed cattle, but the symptoms are 

 essentially the same as in sheep and horses. In regard to post-mortem condi- 

 j tions, they say: 



Numerous autopsies made on locoed sheep and horses revealed conditions which, though 

 fairly uniform, did not constitute a well-defined series. We made a large number of 

 post-mortem examinations upon bodies of locoed sheep which had been killed and bled 

 immediately before examination. In these cases there was no lesion or marked change 

 in the alimentray tract. A slight congestion of the membranes of the brain was to be 

 observed in all cases. The lungs and heart were apparently not affected. The voluntary 

 muscles were of a paler color than under normal conditions, and the fat tissue was con- 

 siderably reduced in quantity. 



As to remedies, the following suggestions have been made : 



L,ocoed sheep should be removed from the band and fattened for market on alfalfa 

 or other forage plants, as above explained. 



The immediate isolation of locoed sheep is advisable in order to prevent the habit 

 from spreading in the band. 



It seems desirable to give sheep a regular and abundant supply of salt in order to pre- 

 vent the development of any perversion of the appetite. 



Locoed horses are used to the best advantage as draft animals, but they must be 

 maintained in good condition and prevented from eating loco weeds. 



Dr. Marsh recommends to cut the roots below the crown of buds. A man 

 with a spade can destroy a large number of plants in a day. The seeds however 

 retain their vitality for some years, hence the field will have to be gone over 

 again. That this method will effectively destroy the plants has been demon- 

 strated by the U. S. Dept. of Agr. atHugo, Colorado. The larvae of a moth 

 (Walshia amorphella) feeds on the purple loco weed and this insect, Dr. 



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