CH&<PTE<R XV. 



GENER&L (DISEASES. 



'Distemper. 



Distemper is a fever originating through infection of the system with a 

 certain peculiar poisonous matter, the nature of which is unknown. By 

 some it is denominated the specific, catarrhal fever of the dog; the name 

 being suggested by the inflammation of the mucous structure which char- 

 acterizes the affection. 



Causation. — When contagion plays so important a part, the existence 

 of a specific germ must he admitted for a disease so clearly defined and 

 so well characterized. Accepting this theory we reach the natural con- 

 clusion that distemper never originates spontaneously, but is dependent 

 upon a transmission, a continued propagation of the disease poison. 

 Some writers found sufficient explanation for the origin of the affection 

 in exposure to damp and cold, ill ventilated kennels, poor food, improper 

 feeding and the like, but as ideas have gradually developed and important 

 advances have been made in tracing to fixed conditions of truth the ori- 

 gins of certain diseases, once believed to have originated by equivocal 

 generation, we can scarcely doubt the doctrine of continuous propagation, 

 and can no longer realize how every considerable deviation from a proper 

 observance of the laws of health should be followed by the production of 

 a particular disease. 



That influences which tend to debilitate are potent factors in the exten- 

 sion of the disease is not questioned, but that it originates only when the 

 specific germ of the disease exists by itself, or has been introduced, must 

 be believed. 



The poison of distemper can be conveyed from one dog to another by 

 contact; but it is true that direct contact is not a necessary condition for 

 transmission; it can be conveyed by the air and in many other ways. 



Hunting in his admirable treatise on this disease states: — "There are 

 certain circumstances favorable to its origin — the congregation together 

 of large numbers of dogs, the transit of clogs through the same places and 



