Six enzyme-linked immunosorbent assays, a latex agglutination test, and the standard microtitration serum virus neutralization test were compared for their ability to detect antibodies against pseudorabies virus (PRV) during the early stages of infection. Thirty-five pigs were infected intranasally with 10(5)-10(7) TCID50 of either the Iowa 4892 pneumotropic or the Becker strain of PRV. Blood samples were drawn from experimentally inoculated animals on days 4-10, 14, and 21 postchallenge. Test sensitivity estimates and comparisons among tests were made for each sampling day over the 21-day monitoring period. Results of this study demonstrated differences among tests in 1) the time from inoculation to initial antibody detection, 2) the time to detect greater than or equal to 95% of the infected pigs, and 3) the time from initial antibody detection to determination of greater than or equal to 95% as positive. By day 10 postchallenge, no statistically significant difference in diagnostic sensitivity was observed among the 8 tests compared in the study.