Preliminary Serologic Survey of Selected Diseases and Movements of Feral Swine in Texas

Feral swine (Sus scrofa) populations occur throughout eastern, central, and southern Texas, and their populations appear to be increasing. Despite their abundance and wide distribution, little is known about their range and interaction with domestic animals. In the last decade the national pork production industry has enforced an eradication program for economically detrimental swine diseases such as pseudorabies and brucellosis. It is hypothesized that feral hogs can be reservoirs that could reintroduce diseases to disease-free domestic swine herds. The objectives of this on-going project are to determine the prevalence of selected swine diseases that exist within feral hog populations in eastern and southern Texas and to determine the potential for disease transmission between feral and domestic swine. To date, feral hogs were trapped and ear-tagged (N = 212), and blood was obtained (N = 163) for serology testing for pseudorabies, brucellosis, and classic swine fever (CSF). Selected adults (N = 57) were fitted with GPS telemetry collars and released at their capture site. Prevalence of brucellosis and pseudorabies was 23.5% and 22.5%, respectively, for feral hogs in Texas. Of the hogs exposed to disease, feral hogs from southern Texas were 3 times as likely to have been exposed to pseudorabies than brucellosis; whereas, the opposite occurred for feral hogs from eastern Texas, which were 3 times more likely to have been exposed to brucellosis than pseudorabies. Prevalence of CSF in feral hogs is pending. Movements of feral hogs in southern Texas indicate that the potential for disease transmission to domestic pigs exists. Data collection will continue for approximately 1.5 years.