CONTROL MEASURES 
The ultimate aim in experimental work in the prevention and control of 
contagious disease is to eliminate the sources and conveyors of the contagium, 
and in the establishment of such immunizing processes as will build up the 
immunity of the possible host to such an extent as will enable it to throw off 
the effects of bacterial invasion. 
Sanitary conditions noted in the investigations in the field during these 
studies could not be rated as better than fair. In most instances the housing 
was poor; the birds were on free range; no germicide was used in the drink¬ 
ing water of the infected flocks to prevent the dissemination of the disease in 
this manner, and although sick birds were isolated, and carcasses safely dis¬ 
posed of, conditions in general favored the inception and spread of disease. 
In moot of the outbreaks investigated the disease had assumed well defined 
FIG. 27.—PHOTOMICROGRAPH OF A TYPHOID KIDNEY. A CLOUDY 
B. SWOLLEN CELLS OCCLUDING THE LUMEN OF TUBULE 
C. CELLS LEAVING BASE 
SWELLING. 
proportions before the owner was sufficiently impressed with its seriousness 
to seek assistance. This fact accounts for the heavy infection of houses and 
premises before remedial steps could be taken to stop the epizootic. As noted 
before, poor sanitation was undoubtedly responsible for the dissemination of 
the disease in the flock after the initial inception. In some of the outbreaks 
investigated the floors and dropping boards had not been cleaned for weeks; 
the food troughs were bespattered with fecal material of long standing, and 
the drinking vessels were clotted with filth and sediment; some of the houses 
were so built as to obtain no direct rays of the sun, and with no provision for 
ventilation. The birds in many cases were of low vitality, suffering severely 
from scabies, internal and external parasites, and the general physical con¬ 
dition of the flocks favored the rapid dissemination of the disease. 
The immediate steps taken to break up the spread of the disease was to 
emphasize strict sanitation, isolation or destruction of sick birds, disinfec- 
