4 BULLETIN" 800, U. S. DEPARTMENT OF AGRICULTTJIIE. 



force engaged in investigating poisonous plants. It was found that 

 during lambing tlie sheep were fed Gunnison Valley hay which 

 contained a considerable quantity of Asclepias galioides. One hun- 

 dred and twenty were said to have been fed, and of that number 

 between 50 and 60 died. The symptoms, as described by the vet- 

 erinarian who was called in, comprised convulsions, rapid pulse 

 and respiration. Nausea and considerable salivation were present. 

 No bloating was noticed. In the autopsy the only l&sion reported 

 was hemorrhagic s|)ots on the heart and lungs. These cases, it 

 should be noticed, were due to the dry plant in the hay. 



About the middle of June, 1918, a letter was received from Assistant 

 District Forester Hatton referring to a heavy loss of sheep near 

 Hotchkiss, Colo., with the suggestion that the matter might be worth 

 more careful investigation. Hotchkiss was reached on June 14 by 

 the senior author, and the next day, in company with Mr. Bennett, 

 who owned the sheep, Mr. Kreutzer, the supervisor of the Gunnison 

 National Forest, and Fred Hotchkiss, of Hotchkiss, he made an ex- 

 amination of the locality. It was found that 1,600 sheep had been 

 kept on a pasture of about 40 acres in the " Midway " region for a 

 day with no feed except that which could be grazed in the pasture. 

 An examination of the pasture showed that the vegetation was largely 

 sagebrush, alfilaria, and Ascle'pi<is galioides. A part of the pasture 

 was an abandoned orchard in which milkweed was abundant. 



The deaths of the sheep had occurred between 2 and 3 weeks before, 

 and in consequence it was somewhat difficult to determine to what 

 extent the milkweed had been grazed. A careful examination, how- 

 ever, showed that it had been eaten in many places, and as there 

 was little else in the pasture it was assumed that the animals had 

 eaten the weed, and that it was the cause of the loss. At that time 

 the weed was from 8 to 15 inches high, and was in bud but with 

 no flowers. It was stated that the animals did not die in the pasture 

 but that symptoms began to appear 2 or 3 hours after they left it. 

 Some of them lived 12 hours after symptoms appeared. The prin- 

 cipal symptoms, according to Mr. Bennett, were violent convulsions, 

 and it was said that the animals would pound their heads upon 

 the ground. Some of the animals became sick as late as 1 o'clock 

 the next day. The total loss was about 400. or about half of those 

 that were sick. 



The weed was found in some other localities between Hotchkiss 

 and Paonia, and Mr. Hotchkiss remarked that he had noticed that 

 when hungry sheep fed upon it many of the sheep died, and that 

 when they avoided the milkweed he lost no sheep, so he felt positive 

 that the milkweed was the cause of the loss. The evidence pointed 

 so strongly to the milkweed that it was deemed probable that it was 

 the real cause of the losses. 



