The detection of Toxoplasma gondii antibodies in free-range chickens (FRC) has become a method for monitoring soil contamination with T. gondii oocysts shed in cat faeces. Although several methods have been employed for T. gondii antibody detection in chicken sera, limited information is available on the use of indirect fluorescent antibody test (IFAT) for this purpose. This study was conducted to determine the occurrence of IgG antibodies to T. gondii in the sera of 241 FRC randomly obtained from 10 local government areas (LGAs) of Oyo state, southwestern Nigeria using IFAT. Antibodies specific for T. gondii were detected in 26 (10.8%) sera with titre of 1:25 in 26 samples, and 1:50 in 5 samples. Seropositive FRC were detected in all 10 LGAs of Oyo State. There was no significant association between T. gondii seroprevalence and age, gender or source of the FRC. The results of the present study show that the IFAT is valuable in detecting antibodies to T. gondii in FRC sera and that infection of these chickens with T. gondii is widespread in the study area. Adequate precautions should be taken during preparation of FRC from the study area for food, as they could serve as potential source of infection for humans.
Key words: Free-range chickens; Toxoplasma gondii, IFAT; Nigeria; Serology