In the early 1900s brucellosis ravaged U.S. cattle and swine, causing
abortions, breeding difficulties, and often sterility. A conserva
ative 1920 estimate was that 15 percent of Minnesota’s dairy
cows we re infected and annual losses to farmers would easily
exceed $100 million in 2004 dollars.
The blood serum test for the disease already was in use in
Eu rope and here when J.B. Fitch came to the Un i versity of
Minnesota in 1917 to head veterinary medicine. Fitch suspected
the accuracy of the brucellosis diagnostic test when, by chance,
he sent his samples to another lab and the results differed greatly
f rom his own. In 1924 Fitch sent identical samples to five laboratories
and found that only 29 percent of the tests agreed. He found the antigen concentration used in the tests was 20 times as great in some labs as in others.
Fitch persuaded three states’ laboratories and the Bu reau of
Animal In d u s t ry to cooperate with the Minnesota laboratory to
standardize their techniques. They then led the drive for national
standards for brucellosis testing. Largely because of his work, the
number of infected U.S. cattle herds declined from millions in
the 1930s to 7,483 in 1978 and fewer than 100 by 1995.
With poultry as with livestock, Station veterinarians played a
large role in research of disease control and pre vention. An international
example is Ben Pomeroy’s diagnostic re s e a rch from the
1930s through the 1980s that combated mycoplasma, bluecomb
virus in turkeys, and Salmonella infectionsa group including
pullorum disease, fowl typhoid, paratyphoid, and related infections.
When Pomeroy began his work on pullorum disease, 40
percent of turkey poults tested by the Veterinary Diagnostic
Laboratory we re found to be infected. By 1956 the disease had
been eradicated from turkeys and Minnesota became the first
state to re c e i ve pullorum-typhoid clean status.