108 VETERINARY STUDIES 



Farmers should not patronize stallions affected with any of 

 these conditions, nor shonld they be misled into purchasing such 

 stallions. The present outlook is that such stallions will be 

 barred from public service in a large number of states within a 

 few years. It should be borne in mind that a fat animal is not 

 necessarily sound or healthy. Domestic animals may be, and 

 frequently are, in show condition, and yet badly diseased. A 

 show bull may be rotten with tuberculosis ; a handsome stallion 

 may be very unsound. Tuberculous cows have broken milk 

 records. 



The spread of tuberculosis in a stable is a good illustration 

 of transmission of disease due to bad air conditions. With an 

 infectious case of tuberculosis already in the herd, tuberculosis 

 spreads much more rapidly in unventilated stables than in well- 

 ventilated stables. Bacteria tend to adhere to whatever they 

 may fall upon and do not Hoat in air, except as carried on dust 

 or other particles. Hence, stable dust becomes an important 

 factor in disseminating disease. But it should be remembered 

 that bacteria differ widely in ability to withstand drying. Most 

 of them do not long remain alive and virulent in contact with 

 dry dust, or dry surfaces in a dry atmosphere. 



Ventilation is very important and should be thorough. It 

 accomplishes several purposes: it admits oxygen, dilutes, re- 

 moves impurities, controls moisture and gives the required air 

 movement. Good ventilation implies rapid change in air with- 

 out direct draughts upon confined animals. Each mature cow 

 or horse should have about 35 square feet of floor space and at 

 least 500 cubic feet of air space, and the air should be renewed 



frequently. 

 Sunshine is even more important, for sunshine is nature's 



universal disinfectant, killing germs of disease. Windows and 



stable frontage should permit of a sweep of sunlight over the 



largest possible surface of floors and fixtures. 



