Location: Animal Parasitic Diseases
2013 Annual Report
Results showed that of the lambs tested, 477 (11.9%) tested positive with a titer of 25 or above. Lambs in the west had the greatest seroprevalence (17.9%) followed by the east (10.6%) and central U.S. (6.1%). The seroprevalence was 13.1% in small and medium operations with 20-499 ewes and 6.4% in operations with 500 or more ewes. By flock type, seroprevalence was 13.8% in operations that managed their sheep on pasture compared with 4.4% in open range flocks. Of the 359 operations that participated in the testing, 45.4% (163) had at least one seropositive animal. By flock size, operation-level prevalence was greatest among operations with 100-499 ewes (48.6%), followed by operations with 20-99 ewes (45.6%) and 500 or more ewes (35.3%). Operation-level prevalence was greatest among operations in the west (58.8%) followed by the east (42.6%) and central U.S. (31.7%).
The observed differences in this study between flocks managed on pasture compared with open range flocks and in flocks with fewer than 500 ewes may be accounted for by greater environmental exposure to T. gondii through the presence of feral and domestic felids and rodents on and near pastures, and to smaller operations that are less intensively managed than feedlots.
These data will interest veterinarians, epidemiologists and producers interested in understanding and limiting human food-borne risk of acquiring Toxoplasmosis.