Disease prevalence and habitat use of feral swine near domestic swine facilities in Texas

Feral swine (Sus scrofa) are present in 38 of the 50 United States, and are widely regarded as a disease threat to domestic swine. Our objectives were to (1) determine seroprevalence of selected diseases in eastern and southern Texas feral swine populations, (2) identify contact events between feral and domestic swine, (3) identify movement and habitat use patterns of feral swine. Feral swine were trapped ≤ 10 km from neighboring domestic swine, sero-tested, and collared with GPS collars. We tested for pseudorabies virus (PRV), swine brucellosis (Brucella spp.), porcine reproductive and respiratory syndrome (PRRS), and classical swine fever (CSF). Overall prevalence of antibodies against brucellosis, PRV, PRRS, and CSF were 11%, 30%, 3%, and 0%, respectively. Movement data was recovered from 37 feral swine. Seven swine contacted (relocated within 100m of) domestic swine. In an experiment using control pens and domestic sow pens, we found greater visitation to the domestic sow pen. Seasonal kernel area values were different between eastern wet (5.93 +/- 4.25 km 2), dry (5.57 +/-3.11 km2), and southern Texas wet (14.07 +/- 10.34 km2), dry (19.5 +/- 15.82 km 2) periods. All three sites had disproportionate habitat use compared to availability. Our data demonstrate that seropositive feral swine utilize habitat around, and have direct contact with, domestic swine presenting opportunity for disease transmission.