N—40816 
Faperateny executives: (I. to r.), Assistant Director 
Manthei, Director William 
vision Director Howard W. Johnson. 
Hagan, Di- 
infectious disease from one animal to 
another—was a key to the conquest of 
malaria, yellow fever, typhus, and other 
insect-borne human and animal diseases. 
Cattle fever research cost $65,000; it led 
to eradication of the disease and an an- 
nual saving to American farmers of 
about a thousand times the initial invest- 
ment. 
The BAI undertook research on other 
major animal and parasitic diseases, 
among them anthrax, blackleg, conta- 
gious bovine pleuropneumonia, fowl chol- 
era, and tuberculosis. 
Hog cholera research also brought 
direct benefits to American farmers. 
After more than 20 years of study, Fed- 
eral veterinarians found that hog cholera 
is caused by a virus. With this knowl- 
edge, they developed a hyperimmune 
serum that protects pigs from the often- 
fatal disease. For many years, simul- 
taneous injections of virus and serum 
were given to hogs; then a killed-virus 
vaccine was developed by the Depart- 
ment scientists. Commercial biologics 
firms introduced improved vaccines in 
16 
the 1940’s. These methods of prevent- 
ing hog cholera have been significant 
in the growth of the Nation’s swine 
industry. 
Long-term research on brucellosis by 
Federal scientists led to the isolation of 
Brucella suis, the cause of the disease in 
swine. Later studies established the re- 
lationship between organisms that cause 
brucellosis in cattle, swine, and goats. 
After the development of Strain 19 vac- 
eine to protect cattle from brucellosis, 
a national eradication program was 
launched. As the brucellosis infection 
rate in cattle declined, undulant fever— 
the form of the disease humans get by 
drinking raw milk from a cow that has 
brucellosis—has declined significantly. 
Federal research workers have tradi- 
tionally cooperated with State and ex- 
periment station scientists in the study 
of disease. Such cooperation solved— 
and eliminated—the problem of X-dis- 
ease, or hyperkeratosis in cattle. In the 
1940’s, a chemical was added to the 
grease commonly used to lubricate feed- 
pelleting machines and sometimes farm 
machinery. Cattle that were fed pelleted 
feed containing traces of the chemical 
became poisoned, and developed thick, 
horny skin. Research workers in 18 
States joined in isolating the cause. 
With the cooperation of lubricant manu- 
facturers, who stopped using the chemi- 
cal, the disease virtually disappeared. 
Another new disease—vesicular exan- 
thema—has been eradicated from the 
United States through the application of 
research. When VE began spreading in 
1952, Federal veterinarians discovered 
that this disease of hogs is spread in con- 
taminated feed, and that heat kills the 
VE virus. After States passed laws re- 
