UNIVERSITY OF VIRGINIA PUBLICATIONS 



BULLETIN OF THE PHILOSOPHICAL SOCIETY 



SCIENTIFIC SECTION 



Vol. I, No. 19, pp. 373-436 March, 1914 



LOCOWEED DISEASE OF SHEEP* 



BY 



HARRY T. MARSHALL. 



(Published by permission of the Secretary of Agriculture.) 



Synonyms: Loco disease, loco, locoism, crazjoveed disease, crazy dis- 

 ease, rattleweed disease. 



There is an opinion widely current that the live stock ranging over the 

 Western plains and Rocky Mountain regions are remarkably free from 

 disease. The general prosperity of the ranch owners has served in great 

 measure to divert attention from the losses and failures befalling certain of 

 their number and it has taken many years to bring a reaUzation of the 

 menace presented by diseases to the continued success of stock raisers in the 

 West. That parasitic diseases occur in sections of the West has been 

 shown by Curtice, Stiles, Ransom, and other members of the Bureau of 

 Animal Industry. Recently Hallf has shown by charts the present 



* The work described in the following report was conducted by me at the request 

 of the U. S. Department of Agriculture, under the supervision of Prof. V. K. Chesnut 

 of the Office of Poisonous Plant Investigation. In addition to his hearty cooperation 

 in many other ways Prof. Chesnut identified the loooweeds used in the experiment 

 and selected the regions over which the loco feeding experiments were conducted. 

 Dr. Charles Wardell Stiles was kind enough to determine the specific identity of the 

 parasites found in my examinations of the sheep during 1903. Mr. B. H. Ransom of the 

 the Bureau of Animal Industry has made a special study describing a new stomach 

 worm of sheep found in the course of my autopsies (Bureau of Animal Industry, 1911, 

 Bull. 127, pp. 62-66). The authorities of the Montana Agricultural College cooperated 

 very courteously with us and moreover performed a valuable and important work in 

 studying the market value of the sheep which were left over from my experiments. 

 Finally, it is a pleasure to acknowledge, even at this late date, my appreciation of 

 the hospitality, interest and assistance everywhere offered us by the ranchmen of 

 Montana. 



fU. S. Bureau of Animal Industry, 27th Report for 1910; pub. 1912, pp. 419-461. 

 373 



NOV 191914 



