Biological Therapy 



143 



In such cases most animals show a chronic though small 

 lung lesion. This consists of an area of red or grey hepati- 

 zation having a glassy appearance and frequently situated 

 in either anterior lobule. The chronicity of the lung lesion 

 and the acuteness of the septicemia lesions make it quite 

 apparent that the pulmonary lesion was present before vac- 

 cination and predisposed the animal to the acute septicemia 

 which follows by maintaining the foci from which the causa- 

 tive organisms (B. suisepticum) migrate. 



DIAGNOSIS. This is ordinarily beset with many diffi- 

 culties and calls for close observation and good judgment. A 

 careful study of the history and symptoms is indispensable. 

 Frequently this makes a diagnosis possible, whereas the 

 same could not be made by autopsy alone. The opinion 

 formed from autopsy findings should be from a compilation 

 of the findings from several autopsies since a single 

 necropsy may be misleading. Since petechia and hemor- 

 rhages are observed in hemorrhagic septicemia, in hog 

 cholera and in other septicemias, it will be apparent that 

 factors other than petechia must be depended upon for diag- 

 nosis. This is particularly true since an animal may be af- 

 fected with both hog cholera and hemorrhagic septicemia at 

 one time. Unless we can be reasonably certain of the free- 

 dom from hog cholera infection this should not be excluded 

 from our diagnosis, whereas if swine are known to have been 

 properly immunized this must of necessity be a factor in 

 arriving at a diagnosis. 



TREATMENT. Unless the possibility of the filterable 

 virus of hog cholera being a factor can be positively ex- 

 cluded, our first treatment should consist of anti-hog-cholera 

 serum, after which supplementary treatment for hemor- 

 rhagic septicemia is advisable. If, however, our diagnosis 

 be incorrect and the disease is hemorrhagic septicemia, or 

 if it be hog cholera complicated by a secondary lung infec- 

 tion caused by B. suisepticum, the simultaneous treatment is 

 certain to be followed by heavy losses. Therefore, the simul- 

 taneous treatment is inadvisable in herds where lung lesions are 

 prevalent. 



In uncomplicated cases where a diagnosis of hemor- 

 rhagic septicemia is certain, either anti-hemorrhagic septi- 

 cemia serum or hemorrhagic septicemia bacterin may be 

 used, although undoubtedly anti-hemorrhagic septicemia 

 serum affords the quickest and most dependable results for 



