CHAPTER XVI 



Specific Infective Diseases 



The horse is liable to suffer from quite a number of 

 specific diseases, that is, diseases due to micro-organisms 

 or germs. These organisms are of an extremely minute 

 size and require high powers of the microscope for their 

 demonstration. Some of these organisms are capable 

 of perpetuation outside the body by means of spores, 

 and may continue their lives for a prolonged period. 

 Nearly the whole of the specific diseases afiecting the 

 horse have been, during the last half-century, scientifi- 

 cally investigated and found to be due to the presence of 

 micro-organisms or bacteria. The older observers had 

 not the facility or requisite appliances for the proper 

 investigation of the maladies now under consideration. 

 The microscope has been the medium for the solution of 

 some of the most complex problems in connection with 

 pathological and bacteriological results. Many hitherto 

 undiscovered causes of disease have been satisfactorily 

 revealed. Moreover, microscopical research has resulted 

 in the production of serums and vaccines, agents which 

 are used both for the prevention and cure of disease, and 

 their value in some cases is indisputable. These diseases 

 are communicable from one horse to another by direct 

 or indirect means ; likewise some of them are transferable 

 to man, and in him may take a short and fatal course, as, 

 for example, glanders and anthrax. The specific infective 

 diseases are nearly all notifiable, that is, if their existence 

 is suspected on any premises the matter must be reported 

 to the local authority of the district, which in some cases, 



146 



