LOCOWEED DISEASE OF SHEEP 385 



yellow pigment than elsewhere in the lobule. In some instances the nuclei in the 

 outer zone of the lobule had entirely disappeared leaving a yellowish pink granular 

 group of cells. In another block from the liver the cells showed the same changes, 

 and, in addition, there was a definite increase in the fibrous tissue around the 

 bile duct and dense accumulations of cells in this region with indications of 

 rather rapid new formation of a fibroblastic tissue. A nodule was found quite 

 sharply marked off, composed for the most part of newly formed fibroblastic cells. 

 A third block from the liver showed again the accumulation of cells around the 

 bile ducts with a beginning fibrosis e,\tending from the ducts into the liver tissue. 

 The degeneration in the outer zone of the lobule was also seen, though not very dis- 

 tinctly. Another section of liver passed through a nodule of very cellular appear- 

 ance, sending a number of branches into the adjacent liver. In this mass were com- 

 pressed liver cells and strands of liver cells. Great numbers of fibroblastic cells, 

 chiefly young, with large vesicular nuclei, and dense accumulations of lymphocytes 

 together with a small number of polymorphonuclears occurred. There were also a 

 number of eosinophiles. At the edges of this nodule the infiltrating cells were seen 

 in between the liver cells very clearly, but it was very difficult to decide whether the 

 cells were chiefly in the lumina of the capillaries or packed between the capillary wall 

 and the liver cell. Both situations appeared to be commonly occupied. Here and 

 there a capillary was found which undoubtedly was plugged by a mass of small deeply 

 stained cells whose nuclei had the appearance of lymphoid cells. Among these occas- 

 sionally was met a large, pale, oval or rounded nucleus. 



The kidney showed cloudy swelling and slight congestion. The adrenal showed 

 pigmentation in the capsule with, apparently, islands of adrenal cells here and there 

 in the capsule. The large vacuolated cells of the medulla also contained dots of brown 

 pigment. A few cysts were found embedded in the muscle of the diaphragm. 



AiiatoJTiical diagnosis. Infection with Thysanosoma aciinioides; obstruction of 

 common bile ducts, cystic, hepatic, and pancreatic ducts; degeneration (infarction?), 

 of a wedge-shaped section of liver with organization, biliary hepatitis; infection of 

 pericardium, liver capsule and omentum with Cyslicercus tenuicollis; loose irregular 

 incisor teeth; emaciation, Sarcocyslis tenella in heart muscle and diaphragm. Cloudy 

 swelling of kidney. Leukocytosis. 



Case No. 3. A flock of 2000 sheep, which had just been driven in from the range 

 to be picked over for the winter, was examined. The flock contained 500 to 800 lambs 

 and yearlings. The sheep herder and the owner (Mr. Vestal) estimated that nearly 

 one-half of the lambs and yearlings were locoed. The examination of the sheep in 

 their corral showed that more than one-half, adults and young ones alike, suffered 

 from coryza and bronchitis. At least one-half of the lambs and yearlings were ema- 

 ciated and moved with a stiff-legged gait. The sheep were more or less sluggish and 

 certainly many of them were very weak. They were not tremulous. They showed no 

 signs of eye or ear defect nor was there any evidence of excitement or mental disturb- 

 ance. They kept in a bunch and did not tend to wander off to the sides of the corral. 

 Not only the young sheep but many of the older ones were unhealthy looking, one 

 of them being so weak it could not rise to its feet. A lamb about five oi; six months 

 old which appeared as severely affected as any that could be found was picked out, 

 chloroformed, bled from the carotid, pelted, and examined at once. 



Autopsy No. 3. September 29, 1903. Lamb, female. Length about 2| feet from 

 tip to tip. Weight hardly more than 12 pounds. Subcutaneous fat practically absent. 



