DISEASES OF TRUE INFECTION. 



Distemper and Contagious Catarrhal Fever. 



The definition of the word ''distemper" describes a disease which is 

 peculiar to the canine race, and it is caused by a specific poison which 

 finds its way into the system, as a rule, through the lungs and air-pas- 

 sages. It generally attacks young animals and runs its course as a 

 catarrhal fever, affecting all the mucous membranes of the body, and is 

 almost invariably accompanied with certain nervous symptoms, and 

 pustular skin eruptions. 



Etiology. — Distemper is a disease which is contagious in the highest 

 degree, and is only communicated by infection. It does not seem to have 

 been recognized or described by the ancients or the writers of the middle 

 ages. An animal aflfectecl with distemper can remain but a short time in 

 any locality and affect every animal there, or it may be transmitted from 

 a person or object that has been in contact with an affected animal. As a 

 rule, few young animals escape distemper, generally contracting it before 

 they are a year old, and dogs over that age very rarely take the disease. 

 That, however, may be accounted for from the fact that dogs having 

 arrived at that age have either come in contact with, the disease previous 

 to that and they have had it in a mild form, or the system was in such a 

 condition, that they did not contract it. The disease affects animals but 

 once during life, although a few exceptions are presented where animals 

 have contracted it a second time. As a rule, delicate, weak, poorly-fed 

 animals (vegetable diet), or animals which have been affected by some 

 catarrhal disorder of the respiratory mucous membranes, contr!ict the 

 disease in its acute form; while, on the other hand, dogs which have lots of 

 exercise, especially animals in the country or small cities, are mildly 

 affected with the disease, and the rate of mortality is much less. 



Distemper exists in all countries of the world. In the large cities it is 

 found at any season of the year, while in the country it is generally more 

 prevalent during the warm weather. The specific poison of distemper is 

 not definitely known. It is undoubtedly a fixed and volatile virus* 

 which enters the system by the mouth and nose, and it exerts its first 



*By a " fixed and volatile virus" we understand a fixed virus that when secreted in the 

 lungs, is carried out in fine division, in the particles of moisture in the expired air, and easily- 

 held in suspension in an atmosphere that contains a slight quantity of humidity. 



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