Auatomieal Changes, Syniptouis. 



641 



Symptoms. The s3'mptoms of this disease consist in 

 gradual emaciation unattended with fever or pain, occasional 

 diarrhea^ (when present usually persistent), the evacuations 

 being thin or watery, frequently containing gas bubbles. The 

 affected animals, though very anemic, do not always show sjanp- 

 tonis of exhaustion even when emaciation has become excessive. 

 On the other hand, the appetite is quite variable, milk produc- 

 tion diminisiics, and tlie disease termii]at(>s fatally after a condi- 

 tion of collapse often lasting several days. In rare cases 

 diarrhea is absent but in spite of this, the disease terminates 

 with sjmiptoms of excessive emaciation and anemia. 



Fij^^ 98. Kntcrliifi chronica paraluhcrculos'.i. Ilypfitropliy of tlie !^^^^ollS Mem- 

 brane of file Small Intestines. 



The course of the disease always extends tlirough several 

 months. Excessive feeding of root crops, and parturition 

 exert an unfavorable influence on its course, while pasturing 

 has a beneficial effect. 



Diagnosis. In some cases where the peculiar intestinal 

 evacuations arouse suspicion of the disease, the diagnosis may 

 1)6 made by a microscopical examination of the intestinal con- 

 tents or of portions of mucous membrane (see p. 6.39; Meyer 

 obtained positive results in 60 to 70% of such cases). The 

 tuberculin test is also of value in this connection, although 

 tuberculin prepared from avian tubercle bacilli must be used. 



Vol. 1^1 



