SPECIFIC DISEASES. 273 



Many conditions have been asserted to be due to tubercular 

 infection, and are sadly lacking in proof. 



Where the disease is suspected, a subcutaneous injection of 

 tuberculin would readily facilitate a correct diagnosis. 



Sbccp pox. Tartola Ovtna. 



This is a very destructive and dangerous disease which fre- 

 quently breaks out among sheep on the European Continent, 

 but which has up to the present time been unknown in the 

 hemispheres of the New World. The reason for this is due to 

 its short period of incubation. Even should infected sheep be 

 shipped across the Atlantic, the disease would break out while they 

 were on shipboard, which would, owing to the excellent meth- 

 ods of inspection and quarantine of imported animals, debar them 

 from becoming a source of danger to the flocks of this country. 

 Should, however, the time ever arise when cattle-boats would 

 make the trip at the same rate of speed made by the present 

 liners the dangers of introduction of this disease would be in- 

 creased considerably and woiUd call for extraordinary efforts on 

 the part of the authorities to overcome the same. 



Causes. 



Beyond a doubt this is a specific disease, although the 

 special contagium or germ responsible for its appearance has not 

 yet been satisfactorily demonstrated. It is a highly contagious 

 affection, and all conditions, such as overcrowding, cold, damp 

 spells of weather, or any such causes which facilitate the spread 

 of other contagious affections, hold good for this disease also. 

 The stage of incubation when arising from natural infection and 

 not experimental inoculation is computed by Prof. Simonds to be 

 from nine to twelve days. The disease may be carried from one 

 locality to another on the clothes of persons who have been in 

 contact with diseased sheep. The contagium contained in the 



