Differential Diagnosis. 589 



Leucemia and pseudo-leucemia. On account of tlie cachexia 

 and the enlarged lymph glands which occur in the course of 

 these diseases they may be confused with tuberculosis. In them, 

 however, the lymph glands are enlarged to an equal degree 

 throughout the body and an examination of the blood in leucemia 

 will reveal the abnormal increase of the white blood cells. 



Chronic meteorism resulting from non-tuberculous affec- 

 tions of the abdominal organs. When due to tuberculous 

 changes, meteorism does not develop to the same intensity 

 and after each temporary attack the accompanying digestive 

 disturbances immediately subside (Albrecht). 



Glanders in horses, especially that form which is confined 

 to the internal organs. The presence of large tumors in the 

 abdominal cavity contraindicate glanders l3ut otherwise a 

 differential diagnosis must be based upon the results of a mallein 

 or tuberculin test. Chronic enlargement of the submaxillary 

 glands does not in itself justify the exclusion of tuberculosis 

 (see p. 562). 



Distemper may be confused with tuberculosis when it is 

 localized in the internal lymph glands and assumes a chronic 

 character. In the clinical examination the anamnesis alone may 

 enable us to make a differential diagnosis. At post-mortem 

 examination the presence of abscesses only and the absence 

 of sarcoma-like structures eliminates tuberculosis. 



Hog cholera. In chronic cases the morbid picture of this 

 disease is very similar to that of tul)erculosis. The anamnesis, 

 however, especially if this shows that the animals in question 

 have previously suffered from acute pulmonary or intestinal 

 affections, will indicate hog cholera as the probable disease while 

 the existence of chronic enlargement of the lymph glands or 

 inflammation of the bones and joints will point to the tuber- 

 culous nature of the affection. At post-mortem small gray 

 or yellowish nodules in the neighborhood of cheesy foci or in 

 the lymph glands indicate tuberculosis. The simultaneous af- 

 fection of a large number of pigs that have been fed with milk 

 or whey is in itself a probable indication of tuberculosis. 



Rachitis, especially in young swdne. In this disease the 

 epiphyses of the bones are enlarged generally while the joints 

 themselves show no symptoms of inflammation. In tuberculosis 

 of the joints the affection is confined to a few joints and there 

 is also swelling of the capsular ligaments. 



Aside from the above named diseases suspicion of tuber- 

 culosis may be aroused in other chronic affections that gradually 

 produce cachexia, especially chronic lung affections. Finally, 

 tuberculous meningitis has many sjonptoms in common with in- 

 flammation of the cerebral meninges from other causes and, 

 similarly, cerebral tuberculosis with neoplasms of the brain, or 

 with eoenurosis. The same may be said with reference to acute 

 miliary tuberculosis and severe acute infectious diseases. 



In contrast with inflammatorv affections of the udder from 



