LOCOWEED DISEASE OF SHEEP 425 



ies, which references in Bulletin 112 allow us to expect. It is, however, 

 clear that Marsh's animals on locoweed diet became ill and died, while 

 controls, not eating locoweed remained healthy. The following analysis 

 of Marsh's publications represents an attempt to construct the clearest 

 possible medical description of Marsh's animals, and incidentally indicates 

 the variations which he mentions. Marsh, (Bureau Animal Industry, Bull. 

 112; 1909, p. 114) claims that "animals eating (the loco plants) succumb 

 sooner or later to their poisonous action." He modifies this statement 

 elsewhere; thus, (Farmer's Bull. 380, p. 10): 



During the spring months, before the grass starts, where the white locoweed is 

 abundant practically all animals eat more or less of it. As the grass becomes more 

 abundant, many of these leave the locoweeds and devote themselves entirely to grass. 

 These animals as a rule do not seem to be injured by the habit. Others . . . 

 continue to eat the locoweed "even where there is an abundance of other feed. 

 Whether an animal will become locoed or not is then simply a matter dependent upon 

 the individual. Some cattle and horses will eat locoweeds for a part of the year, for 

 a period of years and suffer no harm. Others .... eat this plant almost 

 exclusively, and these will die within a few months, or, in some cases, even within 

 a few weeks. 



The same idea occurs also in Bulletin 112 (Case No. 10., etc.) 

 The symptoms were essentially like those popularly described, a stag- 

 gering, stiff, and uncertain gait, the hind legs being dragged frequently; a 

 general disturbance of the nervous system which leads in some cases to an 

 apparent partial paralysis of the limbs and to a very distinct lack of mus- 

 cular coordination. Anaesthesia of the skin may be pronounced. 



"The animals eating loco eat more and more of it, although they do not in all 

 cases acquire a passionate love for the weed, and sooner or later lose flesh, and die of 

 starvation." . . . "The first pronounced symptom (Bull. 246, p. 34) is in the 



gait, which is stiff with more or less evidence of partial paralysis. There is a lack 

 of muscular coordination, which produces 'high stepping,' rearing, jumping and 

 stumbling." In drinking, the mouth moves in a peculiar way, somewhat as in eat- 

 ing. "The animal is either dull and dejected or in constant motion . . 

 It gradually loses flesh, its coat becomes rough, its eyes staring, it becomes pro- 

 foundly anemic, and eventually it dies of starvation." 



Abortion is common among locoed cows. The temperature is usually 

 normal, but varies from subnormal to 108°F. Marsh's colleagues, Peters 

 and Sturdevant, from the Nebraska Agricultural Experiment Station (21st 

 Annual Report, 1908) add to these symptoms, that the horses experimented 

 with showed distinct irregular swellings more or less bilaterally symmetrical, 

 which appeared early on the cheeks and side of the lower jaw as well as 

 "on the place behind the lower lip." Lymphatic enlargement in the inter- 



