562 GENERAL THERAPEUTIC MEASURES 



reactions for diagnosis has also been developed to a remarkable degree in 

 recent years, and without some of these the control of certain diseases 

 would have been impossible. It is especially desired to mention dourine, 

 in which it is impossible to diagnose the latent form without the aid of the 

 complement-fixation and agglutination tests. This applies also to infec- 

 tious abortion in which the affected animals manifest no clinical signs of 

 the infection and a diagnosis can be made only by subjecting the blood of 

 the animals in the suspected herd to either the agglutination or comple- 

 ment-fixation tests. Therefore the importance of these is apparent in the 

 control of these diseases. 



SUMMARY. 



The importance of biologic therapeutics cannot be overestimated. To 

 utilize the forces behind evolution (natural selection, the struggle for ex- 

 istence, the survival of the fittest) in our conflict with bacterial and pro- 

 tozoan infections, through the employment of the dead or living patho- 

 genic organism or its products in our warfare against it, is perhaps the 

 culminating triumph of modern medicine. In employing these means, 

 however, we must always keep in mind certain limitations of this newer 

 therapy. 



Biologic remedies are not specifics in the sense that they will al- 

 ways cure, although in a sense specific for a given disease. They do not 

 always cure or immunize, and the diagnostic agents (examples, tuber- 

 culin, mallein) do not always detect disease. To the trained mind these 

 limitations are not unexpected or disappointing; they exist because the 

 ever-varying individual equation exists. Happily, the best known and 

 longest used are as nearly specific as any remedy can be, as specific as 

 quinine in malarial fever or mercury in syphilis. 



Diphtheria antitoxin, tetanus antitoxin, rabies vaccine, anthrax vac- 

 cine, blackleg filtrate and calf scours serum have given results absolutely 

 unattainable by any other means. 



The accuracy of the diagnostic agents mallein and tuberculin, is so 

 great that we destroy reacting animals that to the clinician appear healthy 

 with absolute confidence that in the great majority of instances the post- 

 mortem examination will justify our diagnosis made solely upon the find- 

 ings of that biologic test. 



The principles of biologic therapeutics are correct ; when we are con- 

 fronted with partial or total failure, it is almost invariably due to the 

 fact that our knowledge is neither complete nor final; each year extends 

 the field of their usefulness, clears our vision and improves our verifiable 

 results. In order to thus profit by this newer therapeutic method we must 

 use biologic remedies early, rather than late, in full, not insufficient dosage ; 

 and must assure ourselves that the remedies we use are potent. Antisepsis 

 must be thorough and the use of the drugs tending to ameliorate symp- 

 toms or conserve the vital powers cannot be neglected. 



In those so common cases where secondary infections complicate the 

 primary we must combat them with all the means* at our command; and 

 in the use of the diagnostic agents only patient taking of temperatures, 

 and rational checking of the symptoms of reaction will safeguard the rep- 

 utation of the practitio^r^^^nd^lg^W/^fare^o^lJs community. 



