DISEASE IN GENERAL 149 



A biologic examination of the secretions, body fluids, and tis- 

 sues may be needed to establish the actual cause of infectious and 

 parasitic diseases. It is useful while the horse is sick as an aid to 

 rational treatment, and very valuable after death in showing what 

 measures are best to follow in protecting other animals from a 

 similar infection. The microscope is the chief aid in this work. 

 Within the last few years several different tests on the blood-serum 

 have been used to advantage in this connection. Those of prac- 

 tical value are the complement-fixation, agglutination, and pre- 

 cipitation tests. The equipment needed to make the various 

 biologic tests will be found only in up-to-date laboratories. 



THE PREVENTION AND CONTROL OF DISEASE 



In recent years in veterinary medicine, as well as general 

 medicine, more attention has been given to the prevention and 

 control of disease than to its treatment. This is one result of the 

 better knowledge of disease processes which has been afforded by 

 the valuable contributions to the study of bacteriology and 

 pathology. We have come to realize that it is much more econom- 

 ical to keep our animals free from disease than to wait until they 

 get sick and then spend both time and money in restoring them to 

 health. The science of preventing the occurrence of disease in and 

 the extension of disease to healthy animals is termed "prophylaxis." 



Prophylaxis consists in attention to hygiene, the proper selec- 

 tion of animals for breeding, the elimination of agents by which 

 infection is spread, and in disinfection and quarantine measures for 

 controlling disease. 



Hygiene is the science and art of conserving and promoting the 

 health. It has for its purpose the regulation of the diet to retain, 

 and strengthen the animal organism by increasing its natural 

 resistance. By following its tenets the greatest degree of bodily 

 health may be secured and premature death prevented. In a 

 broad sense, it includes not only attention to all those things men- 

 tioned in the definition of prophylaxis, but also most of those that 

 are discussed under the section devoted to the treatment of dis- 

 ease. 



The selection of animals for breeding is an important factor in 

 the prevention of disease very frequently overlooked. Careless- 

 ness in attending to this detail of horse husbandry leads to lowered 



