1930s were beginning to be understood in veterinary circles
and applied to animal care. Mastitis and chicken cholera were among the
common diseases brought under control by new drugs. County agents
carried medicine and veterinary equipment with them using it both in
emergency cases and to instruct farmers in sanitation and preventative
care.[112] Health standards, especially for dairy products sold in
Washington, D.C., had been stiffened during the first World War, and it
was important for the farmer to understand disease prevention not only
to save his animals but to keep his produce marketable.

[Illustration: Soybeans on a demonstration field showing the
improvements made by the addition of lime to the soil. Photo in H. B.
Derr Report, 1925, Virginiana Collection, Fairfax County Public
Library.]

Veterinarians abounded in the area, but were called in generally for
required tests (such as tuberculin) or when the situation was really
grave; most farmers relied on their own experience for delivering
calves or treating common ailments.[113] Among the prominent vets in the
county were Dr. Harry Drake, Dr. Bernard Poole and C. L. Kronfeld. All
of these men made house calls, bringing medical kits and medicine with
them. Their fee was $2.50 per visit which included the price of
follow-up medicine. Perhaps because this fee was prohibitive to some, or
through a desire for self-reliance, farmers often neglected to call the
veterinarian until an animal was critically ill. "The farmer in what I
suspect was fifty percent of the cases lost the animal anyway after the
vet got there," acknowledged Joseph Beard,

because so many times instead of having preventative medicine ...
they never called him until things were in very bad shape. I
suspect that the vet would have been able to save so many of the
animals that he didn't by virtue of the fact that he didn't get
there on time.... They weren't interested in prevention; they were
interested in the cure.[114]

The farmers were not entirely to blame since preventative medicine was a
new concept, the benefits of which were not always immediately obvious.
County agents Derr and Beard both waged exhaustive battles to convince
local agriculturalists of the advantage of vaccination and show them the
proper methods of inoculating their own animals. Derr found the farmers
unwilling to do their own vaccinating, preferring to rely on
specialists; yet with cl