Submitted to: American Association of Veterinary Laboratory Diagnosticians
Publication Type: Abstract Only
Publication Acceptance Date: November 3, 2001
Publication Date: N/A
Technical Abstract: The captive Cervidae industry expanded in the United States over the last twenty years. The North American Deer Farmers organization has over 400 members that commercially raise over 75,000 head of fallow (Dama dama), axis (Axis axis), red (Cervus elaphus), white-tailed (Odocoileus virgninianus), or sika deer (Cervus nippon). The North American Elk Breeders Association with over 1700 members, estimates that there are over 150,000 farmed elk (Cervus elaphus) in the United States. Tuberculosis of captive Cervidae became an important disease in the United States in 1990 when investigations were prompted by the identification of a tuberculous elk in Canada that had been imported from the United States in 1988. Testing of domestic herds revealed tuberculosis in 10 different elk herds in 8 different states. Antemortem diagnosis of tuberculosis has relied on measurement of delayed type hypersensitivity (DTH) by intradermal injection of mycobacterial extracts, the most common of which is purified protein derivative (PPD). Few studies have investigated the accuracy of intradermal tuberculin testing in selected species of deer. In the present study, the comparative cervical skin test was done 169 times on 116 different white-tailed deer of known M. bovis infection status. The sensitivity and specificity were 97% and 81% respectively. The results were not significantly influenced by dosage of inoculum, dissemination of the disease process, or repeated skin testing. However, the magnitude of change in skin thickness was significantly greater in deer infected for less than 109 days than in deer infected for more than 109 days.