26 BULLETIN 047, U. S. DEPARTMENT OF AGRICULTURE. 



herders. It is not unusual, when a flock of sheep has been feeding 

 upon a H. hoopesii area, to see large numbers of them throwing up 

 their heads and vomiting. The large sheep in the foreground of 

 figure 3, Plate II, shows the typical attitude of one of these animals 

 in a flock feeding upon the range, and figure 4 of Plate I shows the 

 attitude assumed by a corral force-fed animal in the act of vomiting. 

 Sheep 420, which became ill from prolonged feeding, is shown in 

 Plate II, figure 4, in an attitude produced by nausea. The pictures 

 of Cattle 827 (PL II, figs. 5 and 6) show nausea and vomiting. 



This tendency to vomit may continue for a prolonged period after 

 the feeding upon H. hoopesii has been stopped. The experiences 

 with the animals in 1917 may be quoted as giving a definite idea of 

 the frequency of this symptom. Out of 12 prolonged feedings and 

 2 repeated forced-feeding cases in this year vomiting occurred in 

 8 feedings and in 1 of the repeated forced-feeding cases. Of the 8 

 acute cases in this year only 1 showed a tendency toward vomiting. 



Coughing. — Many of the poisoned sheep were noticed to be fre- 

 quently coughing. This was particularly noticeable in the animals 

 poisoned upon the range. It is probably due to mechanical irrita- 

 tion caused by material from the stomach getting into the larynx. 



Bloating. — Bloat occurred in some of the experimental animals in 

 both acute and chronic cases, and when it occurred was sometimes 

 accompanied with the belching of gas from the stomach. Bloating 

 can not be considered as a usual symptom of the experimental ani- 

 mals. In range cases, however, most of the spewing cases apparently 

 are bloated. 



Trembling. — Trembling was noticed in a number of the cases, but 

 can hardly be considered a characteristic symptom, as it probably 

 results simply from the general weakness of the animal. 



Diarrhea. — In some of the animals diarrhea followed the severe 

 stages of the sickness and was noticeable before complete recovery 

 took place. It was not, however, a usual symptom, and neither it 

 nor constipation can be considered as characteristic of H. hoopesii 



poisoning. 



Most Prominent Symptoms. 



The especially prominent symptoms, then, of H. hoopesii poisoning 

 are general depression, weak and irregular pulse, weakness, and 

 nausea, followed by more or less chronic vomiting. Vomiting is not 

 a characteristic of the acute cases and does not always appear in the 

 chronic cases. Apparently the chronic cases of sheep can be divided 

 into two types — one characterized by extreme weakness with rapid 

 and irregular pulse, and the other with the added symptom of 

 vomiting. 



Death comes on quietly and is not accompanied by convulsions. 

 Plate i, figure 6, shows Sheep 314 in the last stages. 





