DISEASES OF SHEEP. 



CLASSIFICATION OF DISEASES. 



Ever since the most remote ages it has been custom 

 to divide the mass of diseases into classes for greater c 

 venience, and I will here mention some of the most 

 portant for the better understanding of different terms. 



With regard to duration, diseases are divided into-^ 



Short, acute, which do not last longer than three or i 

 weeks ; 



Exceedingly short, which do not last longer than tl 

 days, such as various forms of mortification of the spl 

 and colic ; 



Very short, which terminate on the seventh or tenth d 

 and 



Slow, chronic, which last longer than forty days, and r 

 continue for years, as rot of the lungs. 



Plagues attack many animals — either of the same spec 

 as sheep, or of different species, as horses and cattle, fi 

 the same causes. They are divided into — 



General plagues, epidemics, or epizoics, which origir 

 from external, general, unusual and transitive causes, i 

 commit ravages among the different species in different 

 calities at the same time. 



Local plagues or enzoics, which occur only in cerf 

 localities, and arise from local causes, such as topograph 

 situation, soil, pasture, stables, etc. ; for example, " fluke 



Contagious and non-contagious plagues. The former 

 elude the pox of sheep, mortification of the spleen, can 

 of the tongue, sore mouth, foot rot, scab, pneumonia i 

 diarrhoea. 



Non-contagious plagues are — rot, fluke, lung worms t 

 maggots. 



Single or sporadic diseases are those which atti 



