ARS | Publication request: Shared Feed as a Means of Deer to Deer and Deer to Cattle Transmission of Mycobacterium bovis

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 4, 2009
Publication Date: August 4, 2009
Citation: Palmer, M.V., Thacker, T.C., Waters, W.R. 2009. Shared Feed as a Means of Deer to Deer and Deer to Cattle Transmission of Mycobacterium bovis [abstract]. Minnesota Bovine Tuberculosis Stakeholders Conference. p. 100.

Technical Abstract: Human to human transmission of M. tuberculosis is primarily via a respiratory route. The focus of lesion development in the lungs in human TB patients supports inhalation as a primary means of transmission. The closely related M. bovis is the cause of tuberculosis in most animal species. In white-tailed deer, the most common site for lesion development is the retropharyngeal lymph nodes, suggesting a route other than inhalation as the primary means of disease transmission. To examine shared feed as a possible means of transmission, feed was moved from the pens of infected deer to those of naïve deer for 150 consecutive days. On a daily basis infected deer were fed an excess of feed. After approximately 8 hrs., remaining feed was moved to pens of naïve deer. There was no opportunity for direct contact or aerosol transmission between infected and naïve deer. All naïve deer developed tuberculosis and M. bovis was isolated from multiple tissues. Similarly designed studies using experimentally infected white-tailed deer and naïve 6-month-old calves revealed similar findings in that 44% of calves developed tuberculosis and M. bovis was isolated from multiple tissues. Results of these studies indicate that experimentally infected deer can transmit M. bovis to other deer or cattle through the sharing of feed only, with no opportunity for direct contact or aerosol transmission. In areas where tuberculosis in endemic in free-ranging white-tailed deer, efforts should be made to eliminate intentional and unintentional feeding of wildlife, and preventing access of wildlife to feed intended for cattle.