SYMPTOMS 237 



examination show an enlargement of one or more of the 

 superficial glands, the precrural and the sub-scapular glands 

 being most often involved. The animals thus affected appear 

 in every other respect to be in perfect health. In the older 

 animals, the wethers and breeding ewes, the same glands may 

 be enlarged to a considerable degree, reaching the size of a 

 hen's egg or even larger. Some of these sheep may show a 

 certain degree of unthriftiness or even emaciation. The 

 disease is found in its most advanced stages in the older ewes, 

 which is probably due to the fact that the wethers are gener- 

 ally disposed of before they are three years old, while a good 

 breeding ewe is frequently retained for seven or eight years. 

 In such old animals the superficial lymphatic glands may be 

 enlarged to such a degree as to interfere with locomotion, 

 while the deeper seated glands and those of the body cavities 

 are similarly affected. In the advanced cases the lesions often 

 become disseminated by metastasis to the principal organs of 

 the body. In such cases the disease may assume the appear- 

 ance of chronic broncho-pneumonia or pleurisy, with occa- 

 sional cough, slight dyspnea and increasing emaciation and 

 anemia. The course of the disease is exceedingly slow. For 

 this reason owners of affected flocks are often totally ignorant 

 of the presence of the disease. This fact renders it very difl&- 

 cult to obtain reliable information regarding its prevalence 

 save from the statistics obtained from the slaughter houses. 

 A majority of the inspectors have until recently classified the 

 lesions either as tuberculosis, pyemia or abscesses. In 

 response to inquiries it was found that the majority of cases 

 which had been condemned under these headings were 

 undoubtedly caseous lymph-adenitis. Several thousand cases 

 are annually observed in the slaughter houses of the United 

 States, but only a fraction of these are advanced to a degree 

 that would warrant a total condemnation of the carcasses. 

 Meat inspectors agree that lambs are very rarely affected, and 

 that the progress of the morbid changes in the majority of 

 cases is coordinate with the age of the animal. 



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