ARS | Publication request: Absence of bovine tuberculosis in feral swine (Sus scrofa) from the Southern Texas border region

Submitted to: Journal of Wildlife Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 2, 2011
Publication Date: N/A

Interpretive Summary: A survey of feral swine was conducted in 7 counties, within the Texas border region to determine whether these animals were infested with ticks that might be infected with the serious disease agent, bovine tuberculosis, which could pose a substantial risk to the domestic livestock in the region from exposure, dispersal, and potential transmission of this disease. While a variety of different tick species were found on the hogs that were sampled, fortunately, none of the hogs were infected with the bacteria responsible for causing bovine tuberculosis. The importance of the survey was that it provided encouraging results regarding the absence of this deadly disease in the feral swine population in the sampling area, which greatly reduces the risk of the domestic livestock becoming infected with the disease. However, the survey highlights the critical need for periodic and strategic sampling of feral hog populations to be conducted in areas where this disease occurs naturally to ensure that domestic livestock are protected against the consequences that would occur from an area-wide outbreak of this important disease agent.

Technical Abstract: Free-ranging wildlife, like feral swine (Sus scrofa), harbor a variety of diseases that are infectious to livestock and could negatively impact agricultural production. Information is lacking regarding the exposure and infection rates for bovine tuberculosis (Mycobacterium bovis; bTB), and many other disease and parasites, in feral swine occurring in the Texas border region. Our main objective was to determine exposure rates and possible infection rates of bTB in feral swine by opportunistically sampling feral swine from the Texas border region. Our lymph node histopathology and mycobacterologic cultures, did not detect acid-fast bacteria belonging to the tuberculosis complex. Given the occurrence of bTB within free-ranging Sus scrofa populations worldwide, the absence of bTB in our feral swine samples from this high risk area was encouraging. We believe that it is important to periodically and strategically, sample feral swine for bTB and other disease of agricultural significance in high risk areas of the United States, because they are capable of becoming reservoirs and vectors of these diseases.