A coagglutination test (CT) was developed to detect Brucella, Campylobacter and Salmonella antigens in stomach contents of 58 aborted sheep fetuses and compared with conventional culture techniques. Brucella melitensis, Campylobacter fetus and Salmonella abortus ovis were isolated from 31 (53.4%), 13 (22.4%) and 4 (6.9%) fetuses, respectively. Thirty-five of the fetal stomach contents were positive with the CT test, including 19 (61.3%) with Brucella, 12 (92.3%) with Campylobacter and 4 (100%) with Salmonella CT tests, respectively. Seven samples were negative with all three CT reagents. Cross-reactions were seen with Campylobacter CT (11 samples) and Salmonella CT (six samples). The sensitivity and specificity of the CT tests were 61 and 80% for Brucella, 92 and 80% for Campylobacter, and 100 and 90% for Salmonella, respectively. The CT was found to be technically simple and rapid in diagnosing Salmonella, Campylobacter or Brucella infections by comparison with conventional culture methods. © 2002 Elsevier Science B.V. All rights reserved.