Research Helps Block Spread of
TB in Animals
By Linda McGraw
February 16, 2000
Armed with new knowledge about
transmission of tuberculosis between animals,
Agricultural Research Service scientists
are helping with the effort to eradicate tuberculosis in animals in the United
States. The presence of TB in wild white-tailed deer in Michigan poses a
serious threat to the eradication program. To help fight that problem, ARS
scientists in Ames, Iowa, have developed the first animal model to study TB
transmission in white-tailed deer.
ARS microbiologist Diana Whipple and ARS veterinarian Mitchell V. Palmer
have used the method to experimentally infect captive white-tailed deer with
Mycobacterium bovis, the organism that causes tuberculosis in cattle.
This method helps the researchers study the transmission of TB from
experimentally infected deer to noninfected deer in research pens at ARS
National Animal Disease Center in
One significant finding has already emerged from their studies. The
researchers have identified a possible route of transmission of M. bovis
from experimentally infected deer to other noninfected animals. They found that
deer saliva as well as nasal and tonsil secretions contain M. bovis.
Therefore, a cow or another deer might become infected with M. bovis by
eating feed contaminated with these secretions, according to Whipple.
Fingerprints of genetic material called DNA show that both the wild and
captive deer in Michigan are infected with the identical strain of M.
bovis recovered from coyotes, raccoons, a bear, and cattle.
An article about this work appears in the February issue of Agricultural
Research magazine. The article can be found on the world wide web at:
ARS is the USDAs chief research agency.
Scientific contact: Diana Whipple, ARS National Animal Disease
Center, Ames, Iowa, phone (515) 663-7325, fax (515) 663-7458,