36 DISEASES OP SHEEP. 



or twelve years ; whereas in other parts the reappearance 

 of said disease has not been observed during fifty years. 

 The local situation, the climate and commercial intercourse 

 are very important matters in regard to the formation of 

 said disease. We therefore find that pox is very often 

 imported from foreign countries. Sheep pox may appear 

 at any season and independently of all exterior influences 

 or of the individual constitution of the animal ; affecting 

 the sheep in winter or summer, during the wet and dry 

 season, and befalling young as well as old, healthy as well 

 as sick animals. It seems, however, that certain peculiar 

 qualities of the atmosphere, of the weather, etc, produce 

 an increase or decrease of the disease. 



Sheep pox consists in a feverisli, inflammable eruption 

 of the skin, which is mainly discernible by the formation 

 of inflammable pustules or protuberances upon the skin, 

 secreting a particular fluid, and becoming covered v/ith a 

 certain crust, which at last drops off. The disease is con- 

 tagious in the highest degree, and infects the same animal 

 only once during its life; so that a sheep which has once 

 overcome this disease will never be again subject to it. 



The incidents and progress of this disease are mostly 

 very regular and subject to certain rules. There are four* 

 distinct periods discernible during the progress of said 

 disease, of which, periods each occupies a certain time and 

 presents certain appearances. These periods are called, 

 1, the period of contagion ; 2, of eruption ; 3, of ripeness 

 or maturity ; and 4, of healing or drying off. 



1. Period of contagion. — -Several days (sometimes three 

 or four) after contagion has taken place, the sheep appears 

 to be sullen and weak, head and ears drooping, eating and 

 ruminating less than usual, and showing an increased 

 warmth of skin, especially about the ears. The symptoms, 

 although appearing of so small importance that they are 



