614 Tuberculosis. 



Symptoms. Tuberculosis of tlie internal organs results 

 in gradual emaciation without attendant characteristic symp- 

 toms of specific disease. This condition, which is readily 

 recognized by palpation of the pectoral muscles, progresses in 

 spite of the good appetite that exists in the beginning until 

 the symptoms of anemia, evidenced by the paleness of the 

 mucous membranes, wattles and comb, become more and more 

 pronounced. At a later stage the appetite is affected, the 

 animals become listless, are easily captured, etc. Finally the 

 onset of diarrhea leads to complete exhaustion. 



The symptoms of tuberculosis of the bones and joints 

 are more characteristic. The tarsal, knee and shoulder articula- 

 tions are most frequently affected. They begin to swell 

 gradually and palpation reveals enlargement of the epiphyses. 

 Pain and attendant disturbance of function (lameness, and 

 drooping of the affected wing) is slight at first, but soon be- 

 comes more conspicuous if for no other than 'mechanical 

 reasons. Occasionally the articular swelling breaks open and 

 discharges a cheesy secretion filled with bacilli. 



In rare instances small painless nodules develop in the 

 subcutaneous connective tissue. At a later stage they may 

 ulcerate. Finally, large caseous masses may collect in the 

 cella infraorbitalis, causing enormous distension of the same 

 and attendant pressure atrophy of the eye ball. 



Tuberculosis of the internal organs can hardly be differentiated 

 from chronic disorders of nutrition due to other causes, particularly 

 worms. As a rule the disease is suspected only upon the ground of 

 the apparent infectious nature of the malady. Tuberculosis of the 

 joints is very similar in appearance to rheumatic arthritis or to that 

 form of arthritis which is met with in chronic chicken cholera. These 

 three diseases, however, may readily be differentiated by microscopic 

 examination of the contents of the joints which are easily procured 

 in sufficient quantity by making an incision into the tumefactions. 



The body temperature has no value from a diagnostic point of 

 view since it does not vary beyond the normal limits (39.5° to 41.5° C.) 

 even in tuberculous animals (Klimmer & Saalbeck). 



The tuberculin test is also not applicable because tuberculous fowls 

 will not give specific reactions to tuberculin, no matter whether this 

 is prepared from avian or mammalian bacilli or whether injected sub- 

 cutaneously, dropped into the conjunctival sac or applied to the scarified 

 skin (Babes, "Weber & Bofinger, Moore, Saalbeck). 



Prevention. Since medicinal treatment is practically out 

 of the question and segregation of the diseased animals from 

 the healthy ones is hardly possible on account of the insidious 

 character of the disease the most practical and economical 

 naethod of procedure is to kill the entire flock as soon as the 

 disease is recognized. All animals in good flesh may be utilized 

 as food. The diseased products and organs as well as the 

 entire carcasses of badly affected animals should of course 



