No. 4.] STABLE VENTILATION. 113 



tion of foul and pure air." Our work in Massachusetts during 

 the past ten years in the suppression of tuhcrculosis among 

 cattle has shown that the prevalence of the disease in a herd 

 bears a close relation to the hygienic conditions under which 

 the animals are kept. The more defective the sanitation, the 

 greater the prevalence of the disease. It has also been ob- 

 served that the spread of the disease is much more rapid and 

 the course of it more acute among cattle under unsanitary 

 conditions. The arrest of the disease in animals and its 

 transmission to others can be better controlled by sanita- 

 tion than by the administration of drugs. Animals showing 

 marked symptoms of the disease, such as emaciation and 

 general unthrirtiness, are frequently so much benefited by an 

 improvement in the sanitary conditions about them, or being 

 allowed to run in pasture, that it is quite difficult to detect 

 the disease in them l)y physical examination ; and it is quite 

 generally believed among veterinarians that the disease in its 

 early stages of development may be completely arrested by 

 this method of treatment. 



Glanders among horses furnishes us with another striking 

 example of the relation of poor sanitation to the s[)read and 

 development of a disease. 



In the early part of the present century the yearly loss of 

 horses in the French army from this one disease amounted to 

 2.3 per cent. By an improvement of the sanitary condition 

 about the stables, increasing the cubic capacity and providing 

 a larger supi)ly of fresh air, the deaths from this cause were 

 reduced to .7 per cent. 



It is a well-known fact that horses may suficr from glanders 

 in a chronic form for months, without showing marked 

 symptoms of the disease or without a rapid development of 

 it, provided they are subject to hygienic influences. On the 

 contrary, the disease develops rapidly and assumes an acute 

 character when such animals are removed to damp, dark, 

 ill-ventilated stables. Wounds that under ordinary circum- 

 stances would prove trivial, frequently become gangrenous 

 and prove fatal under similar conditions. 



The same relation exists between unsanitary surroundings 

 and the cause and spread of diseases among other domestic 

 animals as has been shown to exist in tuberculosis in cattle 



