10 BULLETIN" 1012, U. S. DEPARTMENT OF AGRICULTURE. 



milled itself to be bridled or handled in any way, except when penned 

 up at one corner of the corral. On this morning it could be approached 

 easily and did not object to handling. The respiration was faster than 

 normal, and at intervals retching was observed. In searching for 

 the cause of the illness it was found that the horse had eaten some of 

 a mixture of Z. paniculatus and hay that had been thrown into the 

 corral. It was impossible to tell how much he had eaten, so that 

 there was no means of telling what the dosage of the plant had been. 

 The animal showed some abdominal discomfort, and at 9.30 a. m. 

 he was pawing the ground in a manner that indicated some pain. 

 His respiration was about 60 a minute. During the forenoon this 

 condition continued, with prolonged spells of retching, succeeded by 

 profuse salivation. The animal did not stagger or show any unusual 

 weakness. This condition continued during the forenoon and part 

 of the afternoon, but by 4.30 p. m. he had practically recovered. 



As the horse was sick when first seen in the morning it was impossi- 

 ble to tell how long the illness continued, but it must have been at 

 least six hours and perhaps somewhat longer. The case is interesting 

 because the symptoms were entirely comparable with those exhibited 

 by sheep and cattle, but did not continue to the stage of weakness. 

 Plate II, figure 6, shows the attitude which the horse assumed during 

 the acute stage of the illness. 



DISCUSSION AND RESULTS. 



SYMPTOMS. 



Salivation. Salivation appeared in all the cases observed during 

 1919 and 1921, and was the most distinctive symptom. It occurred 

 in 1920 in 3 of the 5 cattle cases, and in 11 of the 13 sheep cases. 

 Salivation in most cases is the first definite evidence of the effect 

 of the plant. This, of course, can not be considered as an especial 

 characteristic of Zygadenus poisoning, because it occurs in a great 

 many forms of intoxication from plants. 



Nausea. Nausea was exhibited in all the cases in 1919. It was 

 common in the experimental animals of 1920 and 1921, but did not 

 appear in all cases, probably because the sickness was not always 

 very pronounced. Sometimes it was indicated only by regurgita- 

 tion. In one of the cattle and six of the sheep it resulted in vomiting. 



Weakness. Muscular weakness occurred in 4 of the 5 cases of 1919, 

 in 3 of the 13 sheep, and 2 of the 5 cattle in 1920, and in 6 of the sheep 

 in 1921. In all but one of the cases this weakness was most pro- 

 nounced in the hind legs and resulted in a characteristic staggering 

 gait. In Sheep 569, which was very sick, and in Sheep 641, which 

 died, this weakness was so pronounced that they were unable to 

 stand. In Sheep 583 and Cattle 784 weakness was the only symp- 

 tom noted except a depression in temperature. This is well shown 

 in Plate II, figures 1 to 4, in the case of Sheep 569. 



