DISEASES OF POrLTRY. 23 



more harm than good will result. In giving medicines 

 intelligently there are three distinct objects which one 

 may attempt to accomplish : 



1. To neutralize, remove or destroy the cause of the 

 disease. 



2. To cause the repair of the affected tissues. 



3. To counteract or remove the symptoms. 



1. As to the first object mentioned, it is clear that we 

 can only direct our remedies towards the cause, when 

 that cause continues to act. In catarrh, pneumonia, 

 inflammation of the intestines, and other diseases which 

 result from exposure to cold, for example, the cause 

 may have been a cold draught of air on a windy night. 

 When the bird is discovered to be sick, a day or two 

 later, the cause is no longer acting. On the other hand, 

 in parasitic diseases, the cause continues to act, as a 

 rule, until it is destroyed ])y remedies or by the vital 

 processes of the body. These examples are simply ill - 

 ustrations of the general fact that there are only a part of 

 the diseases that affect birds, in which an attempt can 

 be made to reach the cause. 



There are special methods of treatment api^licable to 

 the epizoa or external animal parasites, and quite diff- 

 erent methods for the entozoa or internal animal par- 

 asites. Likewise the treatment for epiphytes, or ex- 

 ternal vegetable parasites, may differ widely from that 

 applied to entophytes or internal vegetable parasites. 

 In all these cases, however, we endeavor to remove or 

 destroy the cause of the disease. Poisoning may be 

 treated upon the some principle; that is, an attempt 

 may be made to neutralize, destroy or remove the 

 poison. Whenever possible, the remedies should be 

 directed to the cause of th2 disease, since while this con- 

 tinues to act a cure is im])Ossible. 



